report compilation progress via `xsbti.compile.CompileProgress`

[unkarjedy]

Scala 2 compiler reported compilation progress via xsbti.compile.CompileProgress.
It called both startUnit and advance methods.
This interface is used in IntelliJ Scala Plugin to report compilation progress, both with text and with Compilation Charts

Unfortunately, Scala 3 doesn't use the interface at all.

from https://gitter.im/lampepfl/dotty?at=5ee79bbf7c64f31f11614996

Artyom Semyonov June 15 2020 18:55
Hi all!
I use xsbti.compile.CompileProgress.advance method to show the compilation progress in Scala.
But it seems this method isn't invoking by Dotty compiler.
How can I get the compilation progress information for Dotty?

Guillaume Martres June 15 2020 18:56
well, someone should add calls to advance in dotty

Guillaume Martres June 15 2020 19:03
hmm, CompileProgress is not part of the regular sbt callback interface but a separate thing, so this is going to require some plumbing in dotty

the entry point is https://github.com/lampepfl/dotty/blob/6ab0e6353e575cf2da4ed1c008479694a2671be3/sbt-bridge/src/xsbt/CachedCompilerImpl.java#L57
we pass the AnalysisCallback to dotty via "setSbtCallback(callback)"
so essentially we need another similar method to pass CompileProgress
and then call it when needed, we can just follow the behavior of scalac which appears to be "once per compilation unit per phase completed"

PRs welcome.

related https://youtrack.jetbrains.com/issue/SCL-18400

[unkarjedy]

I will prepare a PR to report phases with startUnit method soon.

[odersky]

@unkarjedy Thanks! Assigning to you then.

[tgodzik]

Did you ever get anywhere @unkarjedy ? Do you need help from someone in the compiler?

[bishabosha]

I will investigate the requirements, can report back by 29th

[bishabosha]

So I have been working on this, callbacks and testing in place, the only tricky part now is adding the calls to track progress