Review Request: JDK-8173978: Lookup.in should allow teleporting from a lookup class in a named module without dropping all access

[Mandy Chung]

On 7/1/19 12:51 PM, Mandy Chung wrote:
> This is an enhancement to |`Lookup::in`| and 
> |`MethodHandles::privateLookupIn`| API
> for cross module teleporting.  A `Lookup` object will record the previous
> lookup class from which this |Lookup| object was teleported such that
> the access check will use both the previous lookup class and the current
> |lookup| context (current lookup class and allowed modes) to determine if
> a type is accessible to this `Lookup` object or not.
>
> In a nutshell, `T` in M2 is accessible to a `Lookup` object on `C`
> (lookup class in M1) and `PLC` (previous lookup class in M0) if and 
> only if
> 1. both M0 and M1 can read M2
> 2. T is in a package that is exported from M2 at least to both M0 and M1
>
> Detailed specification is in Lookup class spec and `accessClass` javadoc.
> The relevant spec about cross-module teleporting is in the Lookup class
> spec and `Lookup::in` and `MethodHandles::privateLookupIn`.
>
> CSR: https://bugs.openjdk.java.net/browse/JDK-8226916
>
> webrev:
> http://cr.openjdk.java.net/~mchung/jdk14/8173978/webrev.00
>
> javadoc:
> http://cr.openjdk.java.net/~mchung/jdk14/8173978/javadoc/java.base/java/lang/invoke/MethodHandles.Lookup.html 
>
>
> http://cr.openjdk.java.net/~mchung/jdk14/8173978/javadoc/java.base/java/lang/invoke/MethodHandles.html#privateLookupIn(java.lang.Class,java.lang.invoke.MethodHandles.Lookup) 
>
>
> I have yet to generate the spec diff. The tool is currently broken
> due to javadoc change.  I'll try to workaround it and post the
> spec diff soon.

specdiff:

http://cr.openjdk.java.net/~mchung/jdk14/8173978/specdiff/overview-summary.html

Mandy