Add support for Scala 3 (#968)

* Add Scala 3 support

* Rename dotty-related version checking methods

Pull request: #968

scalalib/api/src/ZincWorkerApi.scala

@@ -51,9 +51,9 @@ object CompilationResult {
 case class CompilationResult(analysisFile: os.Path, classes: PathRef)
 
 object Util {
-  def isDotty(scalaVersion: String) =
-    scalaVersion.startsWith("0.") ||
-    scalaVersion.startsWith("3.")
+  def isDotty(scalaVersion: String) = scalaVersion.startsWith("0.")
+  def isScala3(scalaVersion: String) = scalaVersion.startsWith("3.")
+  def isDottyOrScala3(scalaVersion: String) = isDotty(scalaVersion) || isScala3(scalaVersion)
 
   // eg, grepJar(classPath, name = "scala-library", versionPrefix = "2.13.")
   // return first path in `classPath` that match:
@@ -82,15 +82,17 @@ object Util {
   val PartialVersion = raw"""(\d+)\.(\d+)\.*""".r
   val ReleaseVersion = raw"""(\d+)\.(\d+)\.(\d+)""".r
   val MinorSnapshotVersion = raw"""(\d+)\.(\d+)\.([1-9]\d*)-SNAPSHOT""".r
-  val DottyVersion = raw"""(0|3)\.(\d+)\.(\d+).*""".r
+  val DottyVersion = raw"""0\.(\d+)\.(\d+).*""".r
+  val Scala3Version = raw"""3\.(\d+)\.(\d+)-(\w+).*""".r
   val DottyNightlyVersion = raw"""(0|3)\.(\d+)\.(\d+)-bin-(.*)-NIGHTLY""".r
   val TypelevelVersion = raw"""(\d+)\.(\d+)\.(\d+)-bin-typelevel.*""".r
 
 
   def scalaBinaryVersion(scalaVersion: String) = scalaVersion match {
       case ReleaseVersion(major, minor, _) => s"$major.$minor"
       case MinorSnapshotVersion(major, minor, _) => s"$major.$minor"
-      case DottyVersion("0", minor, _) => s"0.$minor"
+      case DottyVersion(minor, _) => s"0.$minor"
+      case Scala3Version(minor, patch, milestone) => s"3.$minor.$patch-$milestone"
       case TypelevelVersion(major, minor, _) => s"$major.$minor"
       case _ => scalaVersion
   }
@@ -140,7 +142,8 @@ object Util {
   /** @return true if the compiler bridge can be downloaded as an already compiled jar */
   def isBinaryBridgeAvailable(scalaVersion: String) = scalaVersion match {
       case DottyNightlyVersion(major, minor, _, _) => major.toInt > 0 || minor.toInt >= 14 // 0.14.0-bin or more (not 0.13.0-bin)
-      case DottyVersion(major, minor, _) => major.toInt > 0 || minor.toInt >= 13 // 0.13.0-RC1 or more
+      case DottyVersion(minor, _) => minor.toInt >= 13 // 0.13.0-RC1 or more
+      case Scala3Version(_, _, _) => true
       case _ => false
   }
 }

scalalib/src/Dep.scala

@@ -5,7 +5,7 @@ import upickle.default.{macroRW, ReadWriter => RW}
 import CrossVersion._
 
 case class Dep(dep: coursier.Dependency, cross: CrossVersion, force: Boolean) {
-  import mill.scalalib.api.Util.{isDotty, DottyVersion}
+  import mill.scalalib.api.Util.{isDottyOrScala3, DottyVersion, Scala3Version}
 
   def artifactName(binaryVersion: String, fullVersion: String, platformSuffix: String) = {
     val suffix = cross.suffixString(binaryVersion, fullVersion, platformSuffix)
@@ -54,12 +54,12 @@ case class Dep(dep: coursier.Dependency, cross: CrossVersion, force: Boolean) {
     */
   def withDottyCompat(scalaVersion: String): Dep =
     cross match {
-      case cross: Binary if isDotty(scalaVersion) =>
+      case cross: Binary if isDottyOrScala3(scalaVersion) =>
         val compatSuffix =
           scalaVersion match {
-            case DottyVersion("3", _) =>
+            case Scala3Version(_, _, _) =>
               "_2.13"
-            case DottyVersion("0", minor, patch) =>
+            case DottyVersion(minor, patch) =>
               if (minor.toInt > 18 || minor.toInt == 18 && patch.toInt >= 1)
                 "_2.13"
               else

scalalib/src/Lib.scala

@@ -74,6 +74,10 @@ object Lib{
       Agg(
         ivy"$scalaOrganization::dotty-compiler:$scalaVersion".forceVersion()
       )
+    else if (mill.scalalib.api.Util.isScala3(scalaVersion))
+      Agg(
+        ivy"$scalaOrganization::scala3-compiler:$scalaVersion".forceVersion()
+      )
     else
       Agg(
         ivy"$scalaOrganization:scala-compiler:$scalaVersion".forceVersion(),
@@ -85,16 +89,26 @@ object Lib{
       Agg(
         ivy"$scalaOrganization::dotty-doc:$scalaVersion".forceVersion()
       )
+    else if (mill.scalalib.api.Util.isScala3(scalaVersion))
+      Agg(
+        ivy"$scalaOrganization::scala3-doc:$scalaVersion".forceVersion()
+      )
     else
       // in Scala <= 2.13, the scaladoc tool is included in the compiler
       scalaCompilerIvyDeps(scalaOrganization, scalaVersion)
 
   def scalaRuntimeIvyDeps(scalaOrganization: String, scalaVersion: String) =
-    if (mill.scalalib.api.Util.isDotty(scalaVersion))
+    if (mill.scalalib.api.Util.isDotty(scalaVersion)) {
       Agg(
         // note that dotty-library has a binary version suffix, hence the :: is necessary here
         ivy"$scalaOrganization::dotty-library:$scalaVersion".forceVersion()
       )
+    }
+    else if (mill.scalalib.api.Util.isScala3(scalaVersion))
+      Agg(
+        // note that dotty-library has a binary version suffix, hence the :: is necessary here
+        ivy"$scalaOrganization::scala3-library:$scalaVersion".forceVersion()
+      )
     else
       Agg(
         ivy"$scalaOrganization:scala-library:$scalaVersion".forceVersion()

scalalib/src/ScalaModule.scala

@@ -6,7 +6,7 @@ import mill.define.{Command, Target, Task, TaskModule}
 import mill.eval.{PathRef, Result}
 import mill.modules.Jvm
 import mill.modules.Jvm.createJar
-import mill.scalalib.api.Util.isDotty
+import mill.scalalib.api.Util.{ isDotty, isDottyOrScala3, isScala3 }
 import Lib._
 import mill.api.Loose.Agg
 import mill.api.DummyInputStream
@@ -57,6 +57,8 @@ trait ScalaModule extends JavaModule { outer =>
     val artifacts =
       if (isDotty(scalaVersion()))
         Set("dotty-library", "dotty-compiler")
+      else if (isScala3(scalaVersion()))
+        Set("scala3-library", "scala3-compiler")
       else
         Set("scala-library", "scala-compiler", "scala-reflect")
     if (!artifacts(d.module.name.value)) d
@@ -93,7 +95,7 @@ trait ScalaModule extends JavaModule { outer =>
   def scalacOptions = T{ Seq.empty[String] }
 
   def scalaDocOptions: T[Seq[String]] = T{
-    val defaults = if (isDotty(scalaVersion())) Seq(
+    val defaults = if (isDottyOrScala3(scalaVersion())) Seq(
       "-project", artifactName()
     ) else Seq()
     scalacOptions() ++ defaults
@@ -168,7 +170,7 @@ trait ScalaModule extends JavaModule { outer =>
     val javadocDir = outDir / 'javadoc
     os.makeDir.all(javadocDir)
 
-    if (isDotty(scalaVersion())) {
+    if (isDottyOrScala3(scalaVersion())) {
       // merge all docSources into one directory by copying all children
       for {
         ref <- docSources()
@@ -185,7 +187,7 @@ trait ScalaModule extends JavaModule { outer =>
     val files = allSourceFiles().map(_.path.toString)
 
     val outputOptions =
-      if (isDotty(scalaVersion()))
+      if (isDottyOrScala3(scalaVersion()))
         Seq("-siteroot", javadocDir.toNIO.toString)
       else
         Seq("-d", javadocDir.toNIO.toString)
@@ -210,7 +212,7 @@ trait ScalaModule extends JavaModule { outer =>
       ) match{
         case true =>
           val inputPath =
-            if (isDotty(scalaVersion())) javadocDir / '_site
+            if (isDottyOrScala3(scalaVersion())) javadocDir / '_site
             else javadocDir
           Result.Success(createJar(Agg(inputPath))(outDir))
         case false => Result.Failure("docJar generation failed")
@@ -228,7 +230,7 @@ trait ScalaModule extends JavaModule { outer =>
     }else{
       Jvm.runSubprocess(
         mainClass =
-          if (isDotty(scalaVersion()))
+          if (isDottyOrScala3(scalaVersion()))
             "dotty.tools.repl.Main"
           else
             "scala.tools.nsc.MainGenericRunner",

scalalib/src/ZincWorkerModule.scala

@@ -5,7 +5,7 @@ import mill.T
 import mill.api.{Ctx, FixSizedCache, KeyedLockedCache}
 import mill.define.{Command, Discover, ExternalModule, Worker}
 import mill.scalalib.Lib.resolveDependencies
-import mill.scalalib.api.Util.{isBinaryBridgeAvailable, isDotty}
+import mill.scalalib.api.Util.{isBinaryBridgeAvailable, isDottyOrScala3, isDotty}
 import mill.scalalib.api.ZincWorkerApi
 import mill.util.JsonFormatters._
 
@@ -81,9 +81,11 @@ trait ZincWorkerModule extends mill.Module with OfflineSupportModule { self: Cou
     }
 
     val (bridgeDep, bridgeName, bridgeVersion) =
-      if (isDotty(scalaVersion0)) {
+      if (isDottyOrScala3(scalaVersion0)) {
         val org = scalaOrganization
-        val name = "dotty-sbt-bridge"
+        val name =
+          if (isDotty(scalaVersion0)) "dotty-sbt-bridge"
+          else "scala3-sbt-bridge"
         val version = scalaVersion
         (ivy"$org:$name:$version", name, version)
       } else {

scalalib/worker/src/ZincWorkerImpl.scala

@@ -9,7 +9,7 @@ import java.util.jar.JarFile
 
 import mill.api.Loose.Agg
 import mill.api.{BuildProblemReporter, IO, Info, KeyedLockedCache, PathRef, Problem, ProblemPosition, Severity, Warn}
-import mill.scalalib.api.Util.{grepJar, isDotty, scalaBinaryVersion}
+import mill.scalalib.api.Util.{grepJar, isDotty, isDottyOrScala3, isScala3, scalaBinaryVersion}
 import mill.scalalib.api.{CompilationResult, ZincWorkerApi}
 import sbt.internal.inc._
 import sbt.internal.util.{ConsoleAppender, ConsoleLogger, ConsoleOut, MainAppender}
@@ -115,7 +115,7 @@ class ZincWorkerImpl(compilerBridge: Either[
       compilerClasspath,
       scalacPluginClasspath
     ) { compilers: Compilers =>
-      if (isDotty(scalaVersion)) {
+      if (isDottyOrScala3(scalaVersion)) {
         val dottydocClass = compilers.scalac().scalaInstance().loader().loadClass("dotty.tools.dottydoc.DocDriver")
         val dottydocMethod = dottydocClass.getMethod("process", classOf[Array[String]])
         val reporter = dottydocMethod.invoke(dottydocClass.newInstance(), args.toArray)
@@ -160,7 +160,7 @@ class ZincWorkerImpl(compilerBridge: Either[
       (Seq("javac") ++ argsArray).!
     } else if (allScala) {
       val compilerMain = classloader.loadClass(
-        if (isDotty(scalaVersion)) "dotty.tools.dotc.Main"
+        if (isDottyOrScala3(scalaVersion)) "dotty.tools.dotc.Main"
         else "scala.tools.nsc.Main"
       )
       compilerMain
@@ -345,6 +345,8 @@ class ZincWorkerImpl(compilerBridge: Either[
       val compilerJar =
         if (isDotty(scalaVersion))
           grepJar(compilerClasspath, s"dotty-compiler_${scalaBinaryVersion(scalaVersion)}", scalaVersion)
+        else if (isScala3(scalaVersion))
+          grepJar(compilerClasspath, s"scala3-compiler_${scalaBinaryVersion(scalaVersion)}", scalaVersion)
         else
           compilerJarNameGrep(compilerClasspath, scalaVersion)
 
@@ -355,7 +357,7 @@ class ZincWorkerImpl(compilerBridge: Either[
           compilerClasspath,
           // we don't support too outdated dotty versions
           // and because there will be no scala 2.14, so hardcode "2.13." here is acceptable
-          if (isDotty(scalaVersion)) "2.13." else scalaVersion
+          if (isDottyOrScala3(scalaVersion)) "2.13." else scalaVersion
         ).toIO,
         compilerJar = compilerJar.toIO,
         allJars = combinedCompilerJars,