Initial JDK 11 RFR of JDK-8173382: Add -source 11 and -target 11 to javac - Java Bug System & JDK-8193291: Add SourceVersion.RELEASE_11

[David Holmes]

On 19/12/2017 11:42 AM, Paul Sandoz wrote:
> Looks good to me.
> 
> I am including HS dev for the class file version changes:
> 
> http://cr.openjdk.java.net/~psandoz/jdk/JDK-8173382-classfile-version/webrev/
> http://cr.openjdk.java.net/~psandoz/jdk/JDK-8173382-classfile-version-build-changes/webrev/
> 
> We can push the above patches under the following issue rather that 
> merge into Joe's patch:
> 
> https://bugs.openjdk.java.net/browse/JDK-8191913
> 
> Hopefully by the next release we can merge together and with less 
> changes required.

Changes seem okay, but I'm still a little concerned about using 
classfile version 55 before we actually bump the JDK version to 11.

And it still isn't clear to me who will be doing the actual version 
update and when?

Thanks,
David

> Paul.
> 
>> On 18 Dec 2017, at 17:33, Joseph D. Darcy <joe.darcy at oracle.com 
>> <mailto:joe.darcy at oracle.com>> wrote:
>>
>> Hello,
>>
>> A follow-up on defining a final field RELEASE_CURRENT  as an alias for 
>> the latest SourceVersion constant to allow easier updating of 
>> annotations using SourceVersion constants. Somewht surprisingly, this 
>> is not legal Java code; an annotation must use an enum constant 
>> directly and not a constant expression which evaluates to an enum 
>> constant.
>>
>> This rules is given in JLS 9.7.1 Normal Annotations:
>>
>>> T [ the element type] is not an array type, and the type of V [the 
>>> element value] is assignment compatible (§5.2) with T, and:
>>>
>>>    If T is a primitive type or String, then V is a constant 
>>> expression (§15.28).
>>>    If T is Class or an invocation of Class (§4.5), then V is a class 
>>> literal (§15.8.2).
>>>    If T is an enum type (§8.9), then V is an enum constant (§8.9.1).
>>>    V is not null.
>> https://docs.oracle.com/javase/specs/jls/se9/html/jls-9.html#jls-9.7.1
>>
>> The wording goes back to JLS 3rd edition which introduced enums and 
>> annotations.
>>
>> Formally, the constant expression concept in JLS 15.28 only applies to 
>> primitive types and Strings. Presumably, it would not be too difficult 
>> to expand this concept to include class literals and enum constants.
>>
>> In any case, in the mean time the suggested idiom will not work and 
>> the changes of RELEASE_9 => RELEASE_10 will need to stay.
>>
>> Updated webrev with a minor merge:
>>
>>    http://cr.openjdk.java.net/~darcy/8173382.3/
>>
>> Cheers,
>>
>> -Joe
>>
>