RFR (M) JDK-8033150 (#2): invokestatic: IncompatibleClassChangeError trying to invoke static method from a parent in presence of conflicting defaults
Lois Foltan
lois.foltan at oracle.com
Fri Apr 11 13:04:13 UTC 2014
Please review the updated fix, webrev at:
http://cr.openjdk.java.net/~lfoltan/bug_jdk8033150.1/
This includes Keith's suggestion below. All testing has been rerun
successfully.
Thank you,
Lois
On 3/31/2014 3:51 PM, Lois Foltan wrote:
>
> On 3/31/2014 2:08 PM, Keith McGuigan wrote:
>> Hi Lois,
>>
>> I think that looks good. I like it much better than doing the static
>> method check in the default method processing.
>> My only suggestion is that it would be nice to encode new parameter
>> to uncached_lookup_method to be some sort of enum instead of a
>> boolean, so that it is obvious from the call-site what the behavior
>> should be (having just "false" in the parameter list requires you to
>> reference back to the declaration to figure out what that "false" means).
>>
>> So instead of:
>> uncached_lookup_method(field_name, field_sig, false);
>> It'd be:
>> uncached_lookup_method(field_name, field_sig, NORMAL); or
>> uncached_lookup_method(field_name, field_sig, IGNORE_OVERPASS);
>>
>> (or something like that -- I'm no good at names).
>
> Thank you Keith. Good suggestion. I will implement and repost an
> updated webrev for review.
> Lois
>
>>
>> --
>> - Keith
>>
>>
>> On Mon, Mar 31, 2014 at 1:25 PM, Lois Foltan <lois.foltan at oracle.com
>> <mailto:lois.foltan at oracle.com>> wrote:
>>
>> Hi,
>>
>> Please review the following fix:
>>
>> Webrev:
>> http://cr.openjdk.java.net/~lfoltan/bug_jdk8033150/
>> <http://cr.openjdk.java.net/%7Elfoltan/bug_jdk8033150/>
>>
>> Bug: invokestatic: IncompatibleClassChangeError trying to invoke
>> static method from a parent in presence of conflicting defaults
>> https://bugs.openjdk.java.net/browse/JDK-8033150
>>
>> Summary of fix:
>> During default method processing, determine_target(), is
>> responsible for making decisions on whether
>> to create and add an overpass method to the current class for
>> issues that have been encountered during the walk
>> of the default methods. The routine
>> defaultMethods.cpp/has_matching_static() helped determine this
>> decision by looking within the current class for a static method
>> that should be preferred during method
>> resolution over an overpass method being created. However,
>> has_matching_static() did not continue to
>> look for a static method in current class' superclasses which
>> JDK-8033150 exposed.
>>
>> After looking at the code more closely, the has
>> _matching_static() concept is being moved out out of default
>> method processing and into method resolution processing. The
>> primary reason for this is to allow
>> default method processing to match method selection where statics
>> are and should be ignored. According
>> to JVMS, static methods should only be preferred over an overpass
>> method at method and interface
>> method resolution time. To enable method resolution to
>> potentially find a static method over an overpass
>> method, a new parameter "ignore_overpass" was added to
>> InstanceKlass::uncached_lookup_method().
>> It has the affect of indicating to find_method_index() to ignore
>> overpass methods and continue the search
>> in case a static method of the same name and signature is present
>> in the current class or its superclasses.
>>
>> Tests:
>> - jtreg hotspot/test/*, JDK java.lang & java.util,
>> vm.quick.testlist, JCK lang & vm, defmeth tests
>> - Test will be added to the defmeth test system
>>
>> Thank you,
>> Lois
>>
>>
>
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