Proposed implementation of JEP 182 in JDK 11: drop javac support for -source/-target/--release 6

[Joseph D. Darcy]

Hello,

Based on the feedback on this thread and elsewhere, I've targeted

     JDK-8028563: Remove javac support for 6/1.6 source and target values
     JDK-8173606: Deprecate constructors of 7-era visitors

to JDK 12.

Thanks,

-Joe

On 5/10/2018 10:56 AM, joe darcy wrote:
> Hello,
>
> As background, JEP 182 "Policy for Retiring javac -source and -target 
> Options" (http://openjdk.java.net/jeps/182) puts forth a "one plus 
> three back" policy for the supported range of -source and -target 
> arguments to javac. (As of JDK 9, a matching range of arguments is 
> supported for the --release option.)
>
> This policy was formulated under the old release model before the six 
> month release cadence.
>
> Under this policy, support for the 5/1.5 argument was removed in JDK 
> 9. JDK 10 added support for a 10 argument and retained all the older 
> values that were supported under JDK 9.
>
> JDK 6 first shipped at the end of 2006, which will be nearly 12 years 
> before the planned JDK 11 GA date. JDK 7 first shipped in 2011.
>
> Given the age of JDK 6, I think it is reasonable in 2018 for JDK 11 to 
> drop support for -source/-target/--release 1.6/6, leaving support for 
> 7, 8, 9, 10, and 11. This provides support for four rather than three 
> older versions in JDK 11, but better matches the time span of releases 
> discussed in the JEP.
>
> Future code reviews of the implementation of this removal and related 
> work
>
>     JDK-8028563: Remove javac support for 6/1.6 source and target values
>     JDK-8173606: Deprecate constructors of 7-era visitors
>
> would take place on compiler-dev.
>
> Comments?
>
> Cheers,
>
> -Joe
>