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

[Vladimir Ivanov]

Jochen,

The test provokes the bug, since it sets compilation threshold to 0:
   -Djava.lang.invoke.MethodHandle.COMPILE_THRESHOLD=0

Best regards,
Vladimir Ivanov

On 1/16/14 12:40 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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>>
>
>