RFR: 8013635 Lambda: vm conditionally create bridges for generic signatures

[Bharadwaj Yadavalli]

The updated version looks good.

Thanks,

Bharadwaj

On 6/26/2013 10:52 PM, Karen Kinnear wrote:
> Coleen,
>
> I so appreciate the detailed review - many thanks!
>
> Updated webrev:
>
> http://cr.openjdk.java.net/~acorn/8013635.2/webrev/
>
> tested: with javac and metafactory changes:
> defmeth tests,
> jtreg jdk.util in progress
> vm.quick.testlist in progress
>
> On Jun 25, 2013, at 1:48 PM, Coleen Phillimore wrote:
>
>> Karen,
>>
>> http://cr.openjdk.java.net/~acorn/8013635.1/webrev/src/share/vm/classfile/defaultMethods.cpp.frames.html
>>
>> If someone calls this version of print_on(), won't it call the one at 440 and then crash because signature is null?
>>
>> 437   void print_on(outputStream* str) const {
>> 438     print_on(str, 0);
>> 439   }
>>
> Good catch.
> This is messier than I wanted - so I refactored and renamed some of the print_on's.
>> Shouldn't it just be removed?
>>
>> You could rename "curslotidx" to current_slot_index...
> Done.
>> 774     InstanceKlass* sub = current_depth() > 0 ? class_at_depth(1) : NULL;
>>
>> Variable sub is not used.
> Removed.
>> ShadowChecker::path_has_shadow() should be pure virtual because if you don't override ShadowChecker the visit function will never find a shadow.  line 1088.
>>
> Yes - thank you.
>> 1109       InstanceKlass* sub = class_at_depth(i + 1);
>>
>> Variable 'sub' is not used here (trying to understand this).
> Removed - sorry - left over from the refactoring.
>> 1097 // Only called if the resolved_klass is a direct superinterface of
>> 1098 // the caller's class.
>>
>>
>> This comment seems out of context, in that which is resolved_klass?   Should this comment be in the caller or the caller's caller.  It doesn't seem helpful here to understand what this is doing or why.   Except:
> Removed - and clarified "...candidates which are methods in immediate superinterfaces" - which
> the caller already checks for
>> 1111       if (ik->is_interface()) {
>>
>> And why does this only check for if an interface class shadows the method?  I thought a method of a non-interface class can also shadow a method?
> We are walking up the superinterfaces, so once you get to an interface, the only non-superinterface is j.l.Object which shouldn't
> be providing default methods.
>> 1307   if (!direction->is_interface()) {
>> 1308     // We should not be here
>> 1309     return NULL;
>> 1310   }
>>
>> Should this be an assert instead?   The caller of find_super_default won't be happy to get a NULL back without an exception pending.
> Good catch. Changed to assert, and renamed "direction" to super_class.
>> I don't have any other comments.  This looks good!
>>
>> Coleen
> And thanks for the detailed discussion,
> Karen
>>
>> On 06/20/2013 04:18 PM, Karen Kinnear wrote:
>>> Please review:
>>> https://jbs.oracle.com/bugs/browse/JDK-8013635: BridgeMethodsLinearTest.java fails in
>>> Lambda nightly runs
>>>
>>> webrev: http://cr.openjdk.java.net/~acorn/8013635.1/webrev/
>>>
>>> This particular set of changes modifies the vm to conditionally handle generic signatures
>>> when processing default methods. Basically this code refactors the defaultMethods logic
>>> to work either with generic signatures or only with erased signatures.
>>>
>>> The flag: ParseGenericDefaults is set to "true" in this webrev to continue to work with
>>> the current javac and lambda metafactory components.
>>>
>>> The intention is to change ParseGenericDefaults to false and simultaneously change
>>> javac to generate bridges to handle generic signatures in interface methods, and
>>> the metafactory to no longer generate bridges.
>>> With the flag change, the vm will no longer generate bridges for generic
>>> signatures.
>>>
>>> A subsequent fix: 8012294 will completely remove the vm generic interface handling
>>> for jdk8.
>>>
>>> Please approve this change with both flag settings, so we can coordinate making
>>> those changes in the order that is least disruptive.
>>>
>>> Testing:
>>>
>>> I. hotspot-rt: ParseGenericDefaults=true:
>>> jprt
>>> vm.quick.testlist
>>> jdk-jtreg - in progress
>>> jck-lang, vm - in progress
>>>
>>> II. Lambda repo: ParseGenericDefaults=false:
>>> These two files, with other changes not currently needed - tested in lambda repository for a month
>>>     including tl nightlies and updated BridgeMethodsLinearTest
>>>
>>> III. Current hotspot-rt with these two files only and ParseGenericDefaults=false
>>> with jdk8tl repository with 8015402: metafactory changes and 8013789: javac changes:
>>>
>>> vm.quick.testlist - in progress
>>> jdk-jtreg - in progress
>>> jck-lang, vm - in progress
>>>
>>> thanks,
>>> Karen