semanticdb-scalac + scalamacros/paradise break Scaladoc generation

[olafurpg]

At the following commit
scalacenter/scalafix@9798839
I have the scalahost compiler plugin enabled in the scalafix repo

• coreJVM/compile is OK
• coreJVM/doc fails, build failures https://travis-ci.org/scalacenter/scalafix/jobs/265876123#L698

[error] /home/travis/build/scalacenter/scalafix/scalafix-core/shared/src/main/scala/scalafix/internal/patch/ImportPatchOps.scala:194: don't know how to check whether scala.meta.tokens.Token is scalafix.util.Newline
[error]               val isNewline = x.is[Newline]
[error]                                   ^
[error] /home/travis/build/scalacenter/scalafix/scalafix-core/shared/src/main/scala/scalafix/internal/rewrite/ExplicitReturnTypes.scala:88: don't know how to check whether scala.meta.tokens.Token is scalafix.util.Whitespace
[error]           !x.is[Token.Equals] && !x.is[Whitespace])
[error]                                       ^
[error] /home/travis/build/scalacenter/scalafix/scalafix-core/shared/src/main/scala/scalafix/util/TokenClasses.scala:11: don't know how to check whether scala.meta.tokens.Token is scalafix.util.Newline
[error]     token.is[Space] || token.is[Tab] || token.is[Newline] || token.is[FF]
[error]                                                 ^
[error] /home/travis/build/scalacenter/scalafix/scalafix-core/shared/src/main/scala/scalafix/util/TokenClasses.scala:19: don't know how to check whether scala.meta.tokens.Token is scalafix.util.Whitespace
[error]     token.is[Whitespace] || token.is[Comment]
[error]             ^

The problems seems related to scalamacros/paradise, the following macro annotations in the same projects are not expanded under scaladoc https://github.com/scalacenter/scalafix/blob/016d01cc0286f555bad3ecd898a23ade637786d4/scalafix-core/shared/src/main/scala/scalafix/util/TokenClasses.scala#L7

@xeno-by could analyzer hijacking be conflicting with scalamacros/paradise analyzer hackery under scaladocglobal?

Disabling semanticdb-scalac fixes the problem.

[olafurpg]

This is increasingly annoying since it's blocking me from using scalafix for development in both the scalameta and scalafix repos. Any idea what might be causing this @xeno-by ?

[xeno-by]

Does the issue only occur when paradise is enabled?

[olafurpg]

Yes, scalamacros/paradise annotations are not expanded causing compile errors.

[xeno-by]

Scalamacros/paradise doesn't do any analyzer hijacking, at least not on Scala 2.11+. Instead, it installs so-called analyzer and macro plugins: https://github.com/scalamacros/paradise/blob/2.12.3/plugin/src/main/scala/org/scalamacros/paradise/Plugin.scala#L14-L15.

If I were to guess, I'd say that semanticdb hijacking replaces the analyzer with the paradise plugins installed with the new analyzer that doesn't have these plugins anymore. Why this happens only under scaladoc - that's not immediately obvious.

[olafurpg]

We could skip hijack under ScaladocGlobal. Unlike scalameta/paradise, the sources compile fine withouth semanticdb enabled.

[olafurpg]

I opened #1095 to fix this.