Work around Scala parallel collections situation

Ref scala/scala-parallel-collections#22

Parallel collection got split off without source-compatible library, so apparently we need to roll our own compat hack, which causes import not used, so it needs to be paired with silencer.

build.sbt

@@ -105,6 +105,10 @@ def commonBaseSettings: Seq[Setting[_]] = Def.settings(
   crossScalaVersions := Seq(baseScalaVersion),
   publishArtifact in Test := false,
   fork in run := true,
+  libraryDependencies ++= {
+    if (autoScalaLibrary.value) List(silencerLib)
+    else Nil
+  },
 )
 def commonSettings: Seq[Setting[_]] =
   commonBaseSettings :+
@@ -324,6 +328,10 @@ val logicProj = (project in file("internal") / "util-logic")
     testedBaseSettings,
     name := "Logic",
     mimaSettings,
+    libraryDependencies ++= (scalaVersion.value match {
+      case v if v.startsWith("2.12.") => List(compilerPlugin(silencerPlugin))
+      case _                          => List()
+    }),
   )
 
 // defines Java structures used across Scala versions, such as the API structures and relationships extracted by
@@ -613,6 +621,10 @@ lazy val scriptedSbtReduxProj = (project in file("scripted-sbt-redux"))
     baseSettings,
     name := "Scripted sbt Redux",
     libraryDependencies ++= Seq(launcherInterface % "provided"),
+    libraryDependencies ++= (scalaVersion.value match {
+      case v if v.startsWith("2.12.") => List(compilerPlugin(silencerPlugin))
+      case _                          => List()
+    }),
     mimaSettings,
     scriptedSbtReduxMimaSettings,
   )

main/src/main/scala/sbt/internal/CompatParColls.scala

@@ -0,0 +1,23 @@
+/*
+ * sbt
+ * Copyright 2011 - 2018, Lightbend, Inc.
+ * Copyright 2008 - 2010, Mark Harrah
+ * Licensed under Apache License 2.0 (see LICENSE)
+ */
+
+package sbt.internal
+
+// https://github.com/scala/scala-parallel-collections/issues/22
+private[sbt] object CompatParColls {
+  @com.github.ghik.silencer.silent
+  val Converters = {
+    import Compat._
+    {
+      import scala.collection.parallel._
+      CollectionConverters
+    }
+  }
+  object Compat {
+    object CollectionConverters
+  }
+}

main/src/main/scala/sbt/internal/KeyIndex.scala

@@ -17,12 +17,16 @@ import sbt.librarymanagement.Configuration
 
 object KeyIndex {
   def empty: ExtendableKeyIndex = new KeyIndex0(emptyBuildIndex)
+  @com.github.ghik.silencer.silent
   def apply(
       known: Iterable[ScopedKey[_]],
       projects: Map[URI, Set[String]],
       configurations: Map[String, Seq[Configuration]]
-  ): ExtendableKeyIndex =
+  ): ExtendableKeyIndex = {
+    import sbt.internal.CompatParColls.Converters._
     known.par.foldLeft(base(projects, configurations)) { _ add _ }
+  }
+  @com.github.ghik.silencer.silent
   def aggregate(
       known: Iterable[ScopedKey[_]],
       extra: BuildUtil[_],
@@ -37,6 +41,7 @@ object KeyIndex {
      * This was a significant serial bottleneck during project loading that we can work around by
      * computing the aggregations in parallel and then bulk adding them to the index.
      */
+    import sbt.internal.CompatParColls.Converters._
     val toAggregate = known.par.map {
       case key if validID(key.key.label) =>
         Aggregation.aggregate(key, ScopeMask(), extra, reverse = true)
@@ -92,6 +97,7 @@ object KeyIndex {
   private[sbt] val emptyConfigIndex = new ConfigIndex(Map.empty, Map.empty, emptyAKeyIndex)
   private[sbt] val emptyProjectIndex = new ProjectIndex(Map.empty)
   private[sbt] val emptyBuildIndex = new BuildIndex(Map.empty)
+
 }
 import KeyIndex._
 

main/src/main/scala/sbt/internal/server/Definition.scala

@@ -259,6 +259,7 @@ private[sbt] object Definition {
     result.future
   }
 
+  @com.github.ghik.silencer.silent
   def lspDefinition(
       jsonDefinition: JValue,
       requestId: String,
@@ -287,6 +288,7 @@ private[sbt] object Definition {
         log.debug(s"symbol $sym")
         analyses
           .map { analyses =>
+            import sbt.internal.CompatParColls.Converters._
             val locations = analyses.par.flatMap { analysis =>
               val selectPotentials = textProcessor.potentialClsOrTraitOrObj(sym)
               val classes =

main/src/main/scala/sbt/nio/Settings.scala

@@ -269,7 +269,9 @@ private[sbt] object Settings {
    * @return a task definition that retrieves the input files and their file stamps scoped to the
    *         input key.
    */
+  @com.github.ghik.silencer.silent
   private[sbt] def fileStamps(scopedKey: Def.ScopedKey[_]): Def.Setting[_] = {
+    import sbt.internal.CompatParColls.Converters._
     val scope = scopedKey.scope
     addTaskDefinition(Keys.inputFileStamps in scope := {
       val cache = (unmanagedFileStampCache in scope).value

scripted-sbt-redux/src/main/scala/sbt/scriptedtest/ScriptedTests.scala

@@ -482,6 +482,7 @@ class ScriptedRunner {
       instances: Int
   ) = run(baseDir, bufferLog, tests, logger, launchOpts, prescripted, prop, instances, true)
 
+  @com.github.ghik.silencer.silent
   private[this] def run(
       baseDir: File,
       bufferLog: Boolean,
@@ -510,7 +511,8 @@ class ScriptedRunner {
     val scriptedRunners =
       runner.batchScriptedRunner(scriptedTests, addTestFile, groupCount, prop, logger)
     if (parallelExecution && instances > 1) {
-      val parallelRunners = scriptedRunners.toParArray
+      import sbt.internal.CompatParColls.Converters._
+      val parallelRunners = scriptedRunners.toArray.par
       parallelRunners.tasksupport = new ForkJoinTaskSupport(new ForkJoinPool(instances))
       runAll(parallelRunners)
     } else {
@@ -544,9 +546,12 @@ class ScriptedRunner {
   private def reportErrors(errors: GenSeq[String]): Unit =
     if (errors.nonEmpty) sys.error(errors.mkString("Failed tests:\n\t", "\n\t", "\n")) else ()
 
-  def runAll(toRun: GenSeq[ScriptedTests.TestRunner]): Unit =
+  def runAll(toRun: Seq[ScriptedTests.TestRunner]): Unit =
     reportErrors(toRun.flatMap(test => test.apply().flatten))
 
+  def runAll(toRun: scala.collection.parallel.ParSeq[ScriptedTests.TestRunner]): Unit =
+    reportErrors(toRun.flatMap(test => test.apply().flatten).toList)
+
   @deprecated("No longer used", "1.1.0")
   def get(tests: Seq[String], baseDirectory: File, log: Logger): Seq[ScriptedTest] =
     get(tests, baseDirectory, _ => true, log)