Seemingly erroneous return value in HotSpot test

[Chris Plummer]

I think it should return false like is does with verify_tag(). This will 
cause the test to fail, which it what we would want in this case

Chris

On 9/13/23 11:20 PM, David Holmes wrote:
> Hi Julian,
>
> This is a serviceability issue - cc'd.
>
> On 14/09/2023 12:48 pm, Julian Waters wrote:
>> Hi all,
>>
>> In the HotSpot 
>> test /test/hotspot/jtreg/vmTestbase/nsk/jvmti/IterateThroughHeap/filter-tagged/HeapFilter.cpp, 
>> the method occurance_expected, which returns a jboolean, returns 
>> JNI_ERR in an error condition. The only place this is used is on line 
>> 383, at 
>> https://github.com/openjdk/jdk/blob/11d431b2c436d6b2a0aa7a00d676a93c1b87da0e/test/hotspot/jtreg/vmTestbase/nsk/jvmti/IterateThroughHeap/filter-tagged/HeapFilter.cpp#L383 
>> <https://github.com/openjdk/jdk/blob/11d431b2c436d6b2a0aa7a00d676a93c1b87da0e/test/hotspot/jtreg/vmTestbase/nsk/jvmti/IterateThroughHeap/filter-tagged/HeapFilter.cpp#L383>. 
>> There is no special handling for the JNI_ERR condition as far as I 
>> can tell, and since jboolean is unsigned, the JNI_ERR value of -1 
>> will end up becoming 255 when returning from this method, which is 
>> then interpreted as JNI_TRUE on line 385. I caught this after 
>> redefining jboolean to bool, which then caused the microsoft compiler 
>> to warn about truncating the value. This seems like a bug to me, 
>> since I don't think it should return true on an error condition, is 
>> there something I'm missing?
>
> That's a bug. Unclear whether they intended JNI_FALSE like verify_tag, 
> or whether this was really intended to be an error. If it is an error 
> then the test should abort somehow.
>
> Cheers,
> David
>
>> best regards,
>> Julian