[JDK8] RFR (XS): JSR292: IncompatibleClassChangeError in LambdaForm for CharSequence.toString() method handle type converter

[A. Sundararajan]

The test sets compile threshold to be zero 
(-Djava.lang.invoke.MethodHandle.COMPILE_THRESHOLD=0 ). I think 
compilation occurs on the first invoke.

Also, I ran the test on a jdk8 build without Vladimir's fix - I saw the 
exception being thrown. I ran it by passing the above option in the 
command line (outside jtreg).

-Sundar

On Thursday 16 January 2014 02:10 PM, Jochen Theodorou wrote:
> Hi,
>
> since I am indirectly the reporter of this bug I have one remark for 
> the test. The error happens only for compiled lambda forms. The given 
> test does imho not use a compiled lambda form. In other words, afaik 
> the test would pass without the fix. As such it would be useless as 
> regression test.
>
> Am 15.01.2014 16:31, schrieb Vladimir Ivanov:
>> http://cr.openjdk.java.net/~vlivanov/8031502/webrev.00/
>> https://bugs.openjdk.java.net/browse/JDK-8031502
>>
>> InvokeBytecodeGenerator can produce incorrect bytecode for a LambdaForm
>> when invoking a method from Object declared in an interface.
>>
>> The problem is the following:
>>     (1) java.lang.CharSequence interface declares abstract method 
>> "String
>> toString()";
>>
>>     (2) after 8014013 fix, VM resolves
>> CharSequence::toString()/invokeInterface to
>> CharSequence::toString()/invokeVirtual;
>>
>>     (3) during LambdaForm compilation, CharSequence is considered
>> statically invocable (see
>> InvokeBytecodeGenerator::isStaticallyInvocable) and invokevirtual for
>> CharSequence::toString() is issued, which is wrong (invokevirtual throws
>> ICCE if it references an interface);
>>
>> The fix is straightforward: during LambdaForm compilation, switch back
>> from invokevirtual to invokeinterface instruction when invoking a method
>> on an interface.
>>
>> The fix is targeted for 8. Will be also integrated into 9.
>>
>> Testing: regression test, jdk/test/java/lang/invoke, vm.mlvm.testlist,
>> nashorn, jruby.
>>
>> Thanks!
>>
>> Best regards,
>> Vladimir Ivanov
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>> mlvm-dev at openjdk.java.net
>> http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
>>
>
>