review request for 8010225 test in typeAnnotations/failures do not test TYPE_USE

[Werner Dietl]

Alex,

I think you can't make your conclusion from the SE 7 behavior.
SE 7 by default allows an annotation in any location. So the applicability
check would have succeeded for an unknown annotation. The compiler doesn't
see the FIELD target, because it didn't find the annotation.

I'll look into removing the applicability error for SE 8.

cu, WMD.
On Sep 17, 2013 1:11 PM, "Alex Buckley" <alex.buckley at oracle.com> wrote:

> There should be no applicability check if the annotation's name can't be
> resolved. That's how it worked in SE 7 for the old targets:
>
> @UniqueInner
> class Scopes {
>   @Target(ElementType.FIELD) // Anything but TYPE
>   @interface UniqueInner {}
> }
>
> gives one error, about not finding the symbol UniqueInner in the
> annotation.
>
> I notice that an annotation on a type parameter declaration is treated
> like an annotation on a type use; the following code gives two errors
> (can't resolve + not applicable) but should only give one.
>
> class Scopes<@UniqueInner T> {
>   @interface UniqueInner {}  // Not applicable to type parameter decls
> }
>
> Alex
>
> On 9/17/2013 12:24 PM, Werner Dietl wrote:
>
>> Hi Steve,
>>
>> thanks for testing these cases!
>> In your last case:
>>
>> @UniqueInner
>> class Scopes<T extends @UniqueInner Object> {
>>      @Target(ElementType.TYPE_USE)
>>      @interface UniqueInner { };
>> }
>>
>> The compiler cannot resolve the annotation on the class declaration
>> and on Object and we therefore get the first two errors.
>> Because the compiler cannot resolve the annotation, it doesn't know
>> that it has meta-annotation TYPE_USE. We therefore get the third
>> error, because it sees an annotation in a type-use location without
>> knowing that it has the right meta-annotation.
>>
>> Maybe the check for the TYPE_USE target should be ignored if the
>> annotation can't be resolved?
>> A declaration annotation is by default valid in all locations, so the
>> issue doesn't arise for declaration annotations.
>>
>> Thoughts?
>>
>> cu, WMD.
>>
>>
>> On Tue, Sep 17, 2013 at 12:06 PM, Steve Sides <steve.sides at oracle.com>
>> wrote:
>>
>>> On 9/16/2013 5:20 PM, Alex Buckley wrote:
>>>
>>>>
>>>> On 9/16/2013 2:42 PM, Steve Sides wrote:
>>>>
>>>>>
>>>>> On 9/13/2013 10:42 AM, Alex Buckley wrote:
>>>>>
>>>>>>
>>>>>> - AnnotationVersion: The @summary is imprecise - the test is about the
>>>>>> receiver parameter 'this', not type annotations in general. In SE 6
>>>>>> and 7 and 8, the annotation type 'A' with no
>>>>>>
>>>>>
>>>>> I'm not so sure I agree with that. Due to the 3 @compile lines, the
>>>>> test
>>>>> is about allowing type-annotations only with jdk8. The fact that he put
>>>>> the annotation on 'this' appears to me to be incidental.  It may be odd
>>>>> that he chose 'this' as opposed to maybe 'String' or some other more
>>>>> common usage, but it does seem to be just a usage to make the general
>>>>> point and elicit the diagnostic
>>>>> "compiler.err.type.**annotations.not.supported.in.**source: 1.7", and
>>>>> not to
>>>>> test that specific usage.
>>>>>
>>>>
>>>>
>>>> This test aims to show that "type annotations" didn't exist and now do
>>>> exist. In other words, that an annotation was not permitted in some
>>>> type-oriented location in 6/7 but is permitted in that location in 8.
>>>> It is
>>>> poor form to choose a location in 8 which didn't exist in 6/7 -
>>>> especially
>>>> when that location is frankly very obscure. I would suggest putting the
>>>> @A
>>>> on something simple like an 'extends' clause.
>>>>
>>>> In addition, ElementType.TYPE_USE didn't exist in 6/7 so a reader might
>>>> ask why javac doesn't complain about that rather than the syntax error
>>>> of
>>>> the 'this' parameter. This is why I also suggested having a companion
>>>> test
>>>> where a ElementType from 6/7 was used.
>>>>
>>>> Alex
>>>>
>>>
>>> Got it. While whittling on this, I have another question about the
>>> compiler's behavior.
>>> 1. If I qualify the (not type) annotation,
>>>
>>>    @Scopes.UniqueInner
>>>    class Scopes<T extends @Scopes.UniqueInner Object> {
>>>       @interface UniqueInner { };
>>>    }
>>> I get 1 error, "Scopes.java:11:24:
>>> compiler.err.annotation.type.**not.applicable". This seems correct as
>>> I'm
>>> using an annotation on a type usage, and the one on the class is okay.
>>>
>>> 2. If I use the annotation unqualified, I get 3 errors, two for
>>> "cant.resolve..." and the one above again. I can see that this can also
>>> be
>>> correct.
>>>
>>> Scopes.java:10:2: compiler.err.cant.resolve: kindname.class,
>>> UniqueInner, ,
>>> // on the class
>>> Scopes.java:11:25: compiler.err.cant.resolve: kindname.class,
>>> UniqueInner, ,
>>> // on the bound
>>> Scopes.java:11:24: compiler.err.annotation.type.**not.applicable
>>> // not a type annotation(I assumed)?
>>> 3 errors
>>>
>>> 3. If I use a qualified type annotation,
>>> @Scopes.UniqueInner
>>> class Scopes<T extends @Scopes.UniqueInner Object> {
>>>      @Target(ElementType.TYPE_USE)
>>>      @interface UniqueInner { };
>>> }
>>> it compiles without error.
>>>
>>> 4. However, if I use an unqualified type annotation,
>>> @UniqueInner
>>> class Scopes<T extends @UniqueInner Object> {
>>>      @Target(ElementType.TYPE_USE)
>>>      @interface UniqueInner { };
>>> }
>>>   I get the same 3 errors as the unqualified annotation:
>>>
>>> Scopes.java:10:2: compiler.err.cant.resolve: kindname.class,
>>> UniqueInner, ,
>>> Scopes.java:11:25: compiler.err.cant.resolve: kindname.class,
>>> UniqueInner, ,
>>> Scopes.java:11:24: compiler.err.annotation.type.**not.applicable
>>> 3 errors
>>>
>>> Why should I get "compiler.err.annotation.type.**not.applicable" in
>>> this last
>>> scenario?  For 1. I kind of assumed the third error meant it was not
>>> applicable because it was not a type annotation.  Is it not applicable
>>> for
>>> reasons other than not being TYPE_USE?
>>>
>>> I'm thinking of using it as below (and adding a postivie version with
>>> qualified name),
>>>
>>> @UniqueInner
>>> class Scopes<T extends @UniqueInner Object>  {
>>>      // Unqualified @UniqueInner is not accessible to the class .
>>>      // One has to use @Scopes.UniqueInner.
>>>      @Target(ElementType.TYPE_USE)
>>>      @interface UniqueInner { };
>>> }
>>>
>>> but I'm unsure about that third error and would like to verify it is as
>>> expected.
>>>
>>> -steve
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
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