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List:       openjdk-serviceability-dev
Subject:    Issue with ObjectReferenceImpl.invokeMethod in jdk8  (invocation of an annotation method fails from 
From:       Mike Yawn <mike.yawn () oracle ! com>
Date:       2015-01-22 14:24:26
Message-ID: 54C1081A.4010001 () oracle ! com
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I'm seeing a regression moving from JDK7 to JDK8u40 with the invocation 
of a method in an annotation from a debugger.

I have a simple annotation class with two methods.   There is a unit 
test that retrieves the annotations (getDeclaredAnnotations()).
After retrieving the annotations,  I try to call 
ObjectReference.invokeMethod() to invoke each of the annotation's 
methods.   In JDK7 this worked; in JDK8 it fails with an 
IllegalAccessException: "Not a default method".

I've looked at the source for com.sun.tools.jdi.ObjectReferenceImpl and 
see significant changes between JDK7 and JDK8 due to the introduction of 
interface methods in JDK8.

In JDK7, all methods were class (as opposed to interface) methods and 
the validation of the annotation methods was successful.

In JDK8, validateMethodInvocation has been rewritten to be a small 
method that forwards the validation to one of two new methods, 
validateClassMethodInvocation or validateIFaceMethodInvocation. The 
implementation of validateClassMethodInvocation appears to be the same 
as the pre-JDK8 validateMethodInvocation -- validation that the 
annotation method would pass.   However, the annotation method is being 
treated as an interface method (because method.declaringType() 
instanceof InterfaceTypeImpl is true) and going through 
validateIFaceMethodInvocation.   The test there is that 
method.isDefault() -- and the annotation method returns false, thus the 
exception is thrown.

I'm not sure what the correct behavior is here, but there are a couple 
of possibilities:
- If annotation classes were treated as classes, rather than interfaces, 
then we'd go through the same validation as before and this would work.
- Alternately. if methods on annotations were considered default 
methods, then we'd pass the new validation.   (The annotations do have a 
"default" value specified, but not all annotation methods will, so this 
seems a less satisfactory solution)
- Or, the validateIFaceMethodInvocation may need a special test for 
annotation methods and validate them differently than interface methods.


Do I need to file a bug for this, or is this mailing list a better place 
to report/discuss the issue, or am I doing something wrong that I just 
got away with in JDK7 but JDK8 is closing a loophole, so to speak?

Thanks,
Mike Yawn

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