Use delegating reporter error/warn/info count

[olafurpg]

Following up from discussion in ghik/silencer#7 (comment)

It would be smart if our reporter used info/warn/error counts from the delegating reporter.
Example how this can be done https://github.com/ghik/silencer/blob/099138fff63d3060ddb70be11d65f4cd73e3a6c5/silencer-plugin/src/main/scala/com/github/ghik/silencer/SuppressingReporter.scala#L44-L48
If anyone wants to take a stab at this, a good place to start would be https://github.com/scalameta/scalameta/blob/110147dfa610b7859623ff2aad7f5ee3abbc60b3/semanticdb/scalac/library/src/main/scala/scala/meta/internal/semanticdb/scalac/SemanticdbReporter.scala

[ghik]

The workaround mentioned in ghik/silencer#7 (comment) no longer works because reporters changed in Scala 2.13.1 (scala/scala#8338). SemanticdbReporter needs to be rewritten for Scala 2.13.1+

[olafurpg]

SemanticdbReporter needs to be rewritten for Scala 2.13.1+

Can you elaborate? Our tests are passing on 2.13.1 with the current implementation but if I understand correctly we need to make some changes to make it play nicely with other plugins that also change the reporter?

[ghik]

Yes, the problem only arises in interaction with other compiler plugins like silencer. However, the API used by SemanticdbReporter is deprecated in 2.13.1 so it should be ported anyway. The new API eliminates the necessity to manually track error/warn/info count (thanks to ForwardingReporter)

[olafurpg]

Thanks for the explanation! Makes sense.