RFR JDK-8167442: Langtools ant build not working after addition of -Xlint:exports

[Jan Lahoda]

On 11.10.2016 08:11, Remi Forax wrote:
> I don't think it's a good idea to try to hide these kind of warning
> under the carpet.

Bugs have been filled to every module in OpenJDK for which this warning 
is reported:
https://bugs.openjdk.java.net/browse/JDK-8167176
https://bugs.openjdk.java.net/browse/JDK-8167178
https://bugs.openjdk.java.net/browse/JDK-8167180
https://bugs.openjdk.java.net/browse/JDK-8167181
https://bugs.openjdk.java.net/browse/JDK-8167182
https://bugs.openjdk.java.net/browse/JDK-8167185
https://bugs.openjdk.java.net/browse/JDK-8167187

The warnings have been disabled in the make buildsystem so that the lint 
can be integrated (I suspect that first trying to fix each and every 
violation and then introduce the lint could prove to be too difficult).

>
> It means that the methods are public or the class is in an exported
> package but it should not.

In the specific jdk.jshell case (which we are discussing here), the 
warning is even more strict: in jdk.jshell there are methods like:
JDIExecutionControl.vm()com.sun.jdi.VirtualMachine

com.sun.jdi.VirtualMachine is a public exported type, but in jdk.jdi 
module which the jdk.jshell module does not "re-export" (i.e. the 
jdk.jshell module does not requires public jdk.jdi). So every client of 
this method needs to require jdk.jdi themselves. Whether that is a 
problem in this specific case, I am not sure (I am personally not sure 
if the use of the offending classes in jdk.jshell will be mainstream 
enough to push jdk.jdi to each client of the API).

>
> Hiding this kind of info is harmful IMO.

In this specific case, we are discussing disabling the lint in the 
developer-only ant build script for langtools. The current state blocks 
everyone using the developer-only ant build script (or forces them to 
use private workaround), and I am not sure we should rush some decision 
on whether jdk.jshell should requires public jdk.jdi just to unblock 
people that are using ant.

Jan

>
> Rémi
>
> On October 10, 2016 6:37:39 PM GMT+02:00, Jan Lahoda
> <jan.lahoda at oracle.com> wrote:
>
>     Bug:
>     https://bugs.openjdk.java.net/browse/JDK-8167442
>
>     Proposed solution is to disable the exports lint when compiling the
>     langtools sources (the lint is disabled for the jdk.jshell module when
>     building using the make buildsystem).
>
>     Webrev:
>     http://cr.openjdk.java.net/~jlahoda/8167442/webrev.00/
>
>     Any feedback is welcome.
>
>     Thanks,
>           Jan
>
>
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.