RFR: JDK-8189248: Jshell /open from file generate error when it tries to upcast to typed instance of other with type inferred from it

[Jan Lahoda]

On 5.12.2017 21:43, Robert Field wrote:
> I believe you want the second argument to setWrap to be “legit” rather than “ins” (as on line 807) so that you don’t attempt to import failed snippet names.

Ok, done.

>
> Otherwise looks fine.
>
> It would be good to upgrade the issue Subject so that it will make sense in the future (and include your comments, below).

Done.

Updated webrev:
http://cr.openjdk.java.net/~jlahoda/8189248/webrev.01/

Jan

>
> -Robert
>
> P.S. Apologies, the logic of compileAndLoad is super twisty, I/we should think about a design review.
>
>
>> On Dec 5, 2017, at 6:02 AM, Jan Lahoda <jan.lahoda at oracle.com> wrote:
>>
>> Hi,
>>
>> Consider these snippet sent (in this order) to jshell:
>> ---
>> public class A<T> {
>>   private class SomeClass {}
>>   public Supplier<T> m() {
>>     return new B<>(this);
>>   }
>> }
>> ---
>>
>> (note this depends on the future snippet declaring class B)
>>
>> ---
>> public class B<T> implements Supplier<T> {
>>   public B(A<T> a) {}
>>   public T get() {return null;}
>> }
>> ---
>>
>> Eval.compileAndLoad will after a few rounds try to compile inputs like:
>> ---
>> package REPL;
>>
>> import java.util.function.Supplier;
>> import static REPL.$JShell$3.B;
>>
>> class $JShell$2B {
>>
>>     public static class A<T>
>> ...
>> }
>> ---
>> package REPL;
>>
>> import java.util.function.Supplier;
>> import static REPL.$JShell$2.A;
>>
>> class $JShell$3 {
>>
>>     public static class B<T> implements Supplier<T>
>> ...
>> }
>> ----
>>
>> Please note that "B" is using the old (pre-Unit.markForReplacement()) version of A from $JShell$2. While the new declaration is inside $JShell$2B. I think this is because the classnames are updates only as setWrap(s) run, so the wraps that run first may still see old classnames for the latter snippets.
>>
>> The proposal is to ensure the proper classnames are set before trying to run:
>> ins.stream().forEach(u -> u.setWrap(ins, ins));
>> which creates the real wraps that are processed.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8189248
>> Webrev: http://cr.openjdk.java.net/~jlahoda/8189248/webrev.00/
>>
>> How does it look?
>>
>> Thanks,
>>    Jan
>