[9 + 8u] RFR - 8066612: Add a test that will call getDeclaredFields() on all classes and try to set them accessible.

[Seán Coffey]

Thanks for driving efforts in this area Daniel. I think it's a very 
useful test and is bound to help test code coverage. If it's currently 
passing on all JPRT platforms, it's a good measure.

Eventually I think we can bulk up the tests that can be run on the 
Iterable returned from your class search.
At moment you just test Field.setAccessible.

In the future, I don't see any harm in adding all simple Field method 
calls so that any corner cases in custom classes like the original issue 
are caught. e.g Field.getDeclaredAnnotations(), Field.getModifiers(), 
Field.isEnumConstant() etc., etc. Some methods won't be much value add 
but they're not a cost either.

Same argument for running through all Class methods, e.g 
Class.getDeclaredClasses(), Class.getDeclaredMethods(). As a result this 
test might eventually become more general in test goal and might live 
better one level up in "test/java/lang/Class/" - it can be moved when 
the time comes.

regards,
Sean.

On 04/12/2014 12:25, Daniel Fuchs wrote:
> On 04/12/14 13:06, David Holmes wrote:
>> Hi Daniel,
>>
>> On 4/12/2014 9:38 PM, Daniel Fuchs wrote:
>>> Hi David,
>>>
>>> In fact I could use 'null' on JDK 9 as well.
>>> My first version of the JDK 9 test was parsing over all the .jimage
>>> files under <jdk>/lib/modules - which explain why I needed to
>>> use the System class loader.
>>>
>>> Then I switched to only parsing the bootmodules.jimage - because
>>> I noticed that the results where more coherent with what I had
>>> observed on 8 & 7 - but I kept using the System class loader.
>>>
>>> I am not sure whether we want the test for 9 should iterate over
>>> the three .jimage - or continue to test only the boot .jimage.
>>>
>>> I have updated the JDK 9 test (refreshed the webrev in place)
>>> http://cr.openjdk.java.net/~dfuchs/webrev_8066612/webrev-jdk9.00/
>>> and added support for possibly running the test in the two modes
>>> (I added a 'test.boot.only' system property, true by default)
>>> as well as additional traces to print the loaded classes by
>>> defining loader at the end (test.list.classes, false by default).
>>
>> A couple of initial comments:
>>
>>   104     static ClassLoader getClassLoaderFor(String classFileName) {
>>   105         if (restrictToBoot) return null; // only bootmodules
>>   106         return ClassLoaders.systemClassLoader;
>>   107     }
>>
>> I'm not clear the intent here. If it is to return a loader for which
>> loadClass could be invoked then you can always just return the system
>> loader - or just Class.forName. If it is meant to the return the
>> expected defining loader then it isn't doing that as the extensions
>> loader is not allowed for.
>
> The intent is to return the class loader that will be passed to
> Class.forName( ). I've been fiddling & experimenting with this
> test over 3 different platforms while trying to minimize the
> differences - so that was my attempt at having a good place to
> experiment with different strategy for loading classes.
>
>> Similarly for:
>>
>>   128         static ClassLoader getFor(String classFileName) {
>>   129             return systemClassLoader;
>>   130         }
>
> Oh - that's my mistake. In fact ClassLoader getClassLoaderFor(..)
> was supposed to simply return ClassLoaders.getFor(...);
> and all the code should be in ClassLoaders.getFor - my bad.
>
>> Minor nit - In:
>>
>> 135                     System.err.println("Unexpected loader for "+c+":
>> "+c.getClassLoader());
>>
>> c.getClassLoader() can be replaced by cl. Also put spaces around the +
>> operator.
>
> Good catch.
>
> Thanks a lot David! Have a good night! (that's quite late - isn't it?)
>
> -- daniel
>
>>
>> David
>> (signing off for the night)
>>
>>> Thanks for your question, it triggered me into looking deeper
>>> into what was happening :-)
>>>
>>> best regards,
>>>
>>> -- daniel
>>>
>>> On 04/12/14 10:05, Daniel Fuchs wrote:
>>>>>> The differences between 8 & 9 are limited to:
>>>>>>
>>>>>>     - ClassLoader:
>>>>>>          - on 8 we use 'null' (BCL)
>>>>>>          - on 9 we use the system class loader.
>>>>>
>>>>> I haven't seen anything in JEP 220, regarding modules, that indicates
>>>>> that classes currently loaded  by the boot-loader will now be loaded
>>>>> by the system classloader ???
>>>>
>>>> In [1] towards the end:
>>>>
>>>> [1] http://openjdk.java.net/jeps/220
>>>>
>>>> "The defining class loader of the types in some existing packages
>>>>   will change. Existing code that makes assumptions about the class
>>>>   loaders of these types might not work correctly."
>>>>   (then there is a list of specific changes).
>>>>
>>>> This test looks up all class names in the image files and attempt
>>>> to load the corresponding class. But as indicated in [1]
>>>> some of these classes are now in the Boot CL, some in the
>>>> Extension CL, and some in the Application CL.
>>>>
>>>> So the test uses the System CL to load each class - which ensures
>>>> that the loading will be delegated to the appropriate ClassLoader.
>>>>
>>>> best regards,
>>>>
>>>> -- daniel
>>>
>