compile zinc compiler bridges on demand to remove restriction on supported scala versions

6 files changed, 30 insertions, 43 deletions

diff --git a/scalalib/src/mill/scalalib/GenIdea.scala b/scalalib/src/mill/scalalib/GenIdea.scala
index ea401b04..6511ee25 100644
--- a/scalalib/src/mill/scalalib/GenIdea.scala
+++ b/scalalib/src/mill/scalalib/GenIdea.scala
@@ -45,7 +45,6 @@ object GenIdea {
           val Result.Success(res) = scalalib.Lib.resolveDependencies(
             Seq(Cache.ivy2Local, MavenRepository("https://repo1.maven.org/maven2")),
             "2.12.4",
-            "2.12",
             for(name <- artifactNames)
             yield Dep("com.lihaoyi", s"mill-${name}", "0.0.1-SNAPSHOT")
           )
diff --git a/scalalib/src/mill/scalalib/Lib.scala b/scalalib/src/mill/scalalib/Lib.scala
index 8fbbfc0f..ae10bd00 100644
--- a/scalalib/src/mill/scalalib/Lib.scala
+++ b/scalalib/src/mill/scalalib/Lib.scala
@@ -18,6 +18,8 @@ case class CompilationResult(analysisFile: Path, classes: PathRef)
 
 object Lib{
 
+  def scalaBinaryVersion(scalaVersion: String) = scalaVersion.split('.').dropRight(1).mkString(".")
+
   def grepJar(classPath: Agg[Path], s: String) = {
     classPath
       .find(_.toString.endsWith(s))
@@ -34,13 +36,12 @@ object Lib{
     */
   def resolveDependencies(repositories: Seq[Repository],
                           scalaVersion: String,
-                          scalaBinaryVersion: String,
                           deps: TraversableOnce[Dep],
                           sources: Boolean = false): Result[Agg[PathRef]] = {
     val flattened = deps.map{
       case Dep.Java(dep) => dep
       case Dep.Scala(dep) =>
-        dep.copy(module = dep.module.copy(name = dep.module.name + "_" + scalaBinaryVersion))
+        dep.copy(module = dep.module.copy(name = dep.module.name + "_" + scalaBinaryVersion(scalaVersion)))
       case Dep.Point(dep) =>
         dep.copy(module = dep.module.copy(name = dep.module.name + "_" + scalaVersion))
     }.toSet
diff --git a/scalalib/src/mill/scalalib/PublishModule.scala b/scalalib/src/mill/scalalib/PublishModule.scala
index 64efce77..cedcdf8a 100644
--- a/scalalib/src/mill/scalalib/PublishModule.scala
+++ b/scalalib/src/mill/scalalib/PublishModule.scala
@@ -15,7 +15,7 @@ trait PublishModule extends ScalaModule { outer =>
 
   def pom = T {
     val dependencies =
-      ivyDeps().map(Artifact.fromDep(_, scalaVersion(), scalaBinaryVersion()))
+      ivyDeps().map(Artifact.fromDep(_, scalaVersion(), Lib.scalaBinaryVersion(scalaVersion())))
     val pom = Pom(artifact(), dependencies, artifactName(), pomSettings())
 
     val pomPath = T.ctx().dest / s"${artifactId()}-${publishVersion()}.pom"
@@ -25,7 +25,7 @@ trait PublishModule extends ScalaModule { outer =>
 
   def ivy = T {
     val dependencies =
-      ivyDeps().map(Artifact.fromDep(_, scalaVersion(), scalaBinaryVersion()))
+      ivyDeps().map(Artifact.fromDep(_, scalaVersion(), Lib.scalaBinaryVersion(scalaVersion())))
     val ivy = Ivy(artifact(), dependencies)
     val ivyPath = T.ctx().dest / "ivy.xml"
     write.over(ivyPath, ivy)
diff --git a/scalalib/src/mill/scalalib/ScalaModule.scala b/scalalib/src/mill/scalalib/ScalaModule.scala
index 8f635906..47326c6c 100644
--- a/scalalib/src/mill/scalalib/ScalaModule.scala
+++ b/scalalib/src/mill/scalalib/ScalaModule.scala
@@ -7,10 +7,12 @@ import mill.define.{Cross, Task}
 import mill.define.TaskModule
 import mill.eval.{PathRef, Result}
 import mill.modules.Jvm
-import mill.modules.Jvm.{createAssembly, createJar, interactiveSubprocess, subprocess, runLocal}
+import mill.modules.Jvm.{createAssembly, createJar, interactiveSubprocess, runLocal, subprocess}
 import Lib._
 import mill.define.Cross.Resolver
 import mill.util.Loose.Agg
+import mill.util.Strict
+
 /**
   * Core configuration required to compile a single Scala compilation target
   */
@@ -23,7 +25,6 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
   def scalaVersion: T[String]
   def mainClass: T[Option[String]] = None
 
-  def scalaBinaryVersion = T{ scalaVersion().split('.').dropRight(1).mkString(".") }
   def ivyDeps = T{ Agg.empty[Dep] }
   def compileIvyDeps = T{ Agg.empty[Dep] }
   def scalacPluginIvyDeps = T{ Agg.empty[Dep] }
@@ -60,7 +61,6 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
     resolveDependencies(
       repositories,
       scalaVersion(),
-      scalaBinaryVersion(),
       deps(),
       sources
     )
@@ -90,31 +90,13 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
     depClasspath()
   }
 
-  /**
-    * Strange compiler-bridge jar that the Zinc incremental compile needs
-    */
-  def compilerBridge: T[PathRef] = T{
-    val compilerBridgeKey = "MILL_COMPILER_BRIDGE_" + scalaVersion().replace('.', '_')
-    val compilerBridgePath = sys.props(compilerBridgeKey)
-    if (compilerBridgePath != null) PathRef(Path(compilerBridgePath), quick = true)
-    else {
-      val dep = compilerBridgeIvyDep(scalaVersion())
-      val classpath = resolveDependencies(
-        repositories,
-        scalaVersion(),
-        scalaBinaryVersion(),
-        Seq(dep)
-      )
-      classpath match {
-        case Result.Success(resolved) =>
-          resolved.filter(_.path.ext != "pom").toSeq match {
-            case Seq(single) => PathRef(single.path, quick = true)
-            case Seq() => throw new Exception(dep + " resolution failed") // TODO: find out, is it possible?
-            case _ => throw new Exception(dep + " resolution resulted in more than one file")
-          }
-        case f: Result.Failure => throw new Exception(dep + s" resolution failed.\n + ${f.msg}") // TODO: remove, resolveDependencies will take care of this.
-      }
-    }
+  def compilerBridgeSources = T{
+    resolveDependencies(
+      repositories,
+      scalaVersion(),
+      Seq(ivy"org.scala-sbt::compiler-bridge:1.1.0"),
+      sources = true
+    )
   }
 
   def scalacPluginClasspath: T[Agg[PathRef]] =
@@ -153,10 +135,10 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
     mill.scalalib.ScalaWorkerApi.scalaWorker().compileScala(
       scalaVersion(),
       allSources().map(_.path),
+      compilerBridgeSources().map(_.path),
       compileDepClasspath().map(_.path),
       scalaCompilerClasspath().map(_.path),
       scalacPluginClasspath().map(_.path),
-      compilerBridge().path,
       scalacOptions(),
       scalacPluginClasspath().map(_.path),
       javacOptions(),
@@ -270,7 +252,7 @@ trait ScalaModule extends mill.Module with TaskModule { outer =>
   def artifactName: T[String] = basePath.last.toString
   def artifactScalaVersion: T[String] = T {
     if (crossFullScalaVersion()) scalaVersion()
-    else scalaBinaryVersion()
+    else Lib.scalaBinaryVersion(scalaVersion())
   }
 
   def artifactId: T[String] = T { s"${artifactName()}_${artifactScalaVersion()}" }
diff --git a/scalalib/src/mill/scalalib/ScalaWorkerApi.scala b/scalalib/src/mill/scalalib/ScalaWorkerApi.scala
index 7db48a41..4f9c527c 100644
--- a/scalalib/src/mill/scalalib/ScalaWorkerApi.scala
+++ b/scalalib/src/mill/scalalib/ScalaWorkerApi.scala
@@ -1,7 +1,5 @@
 package mill.scalalib
 
-import java.lang.reflect.{InvocationHandler, Method}
-import java.net.URI
 
 import ammonite.ops.Path
 import coursier.Cache
@@ -9,8 +7,7 @@ import coursier.maven.MavenRepository
 import mill.Agg
 import mill.scalalib.TestRunner.Result
 import mill.T
-import mill.define.{Task, Worker}
-import mill.eval.PathRef
+import mill.define.Worker
 import mill.scalalib.Lib.resolveDependencies
 import mill.util.Loose
 import mill.util.JsonFormatters._
@@ -22,7 +19,6 @@ object ScalaWorkerApi extends mill.define.ExternalModule {
       val mill.eval.Result.Success(v) = resolveDependencies(
         Seq(Cache.ivy2Local, MavenRepository("https://repo1.maven.org/maven2")),
         "2.12.4",
-        "2.12",
         Seq(ivy"com.lihaoyi::mill-scalaworker:0.0.1-SNAPSHOT")
       )
       v.map(_.path)
@@ -34,18 +30,27 @@ object ScalaWorkerApi extends mill.define.ExternalModule {
       getClass.getClassLoader
     )
     val cls = cl.loadClass("mill.scalaworker.ScalaWorker")
-    val instance = cls.getConstructor(classOf[mill.util.Ctx]).newInstance(T.ctx())
+    val instance = cls.getConstructor(classOf[mill.util.Ctx], classOf[Array[String]])
+      .newInstance(T.ctx(), compilerInterfaceClasspath().map(_.path.toString).toArray[String])
     instance.asInstanceOf[ScalaWorkerApi]
   }
+
+  def compilerInterfaceClasspath = T{
+    resolveDependencies(
+      Seq(Cache.ivy2Local, MavenRepository("https://repo1.maven.org/maven2")),
+      "2.12.4",
+      Seq(ivy"org.scala-sbt:compiler-interface:1.1.0")
+    )
+  }
 }
 
 trait ScalaWorkerApi {
   def compileScala(scalaVersion: String,
                    sources: Agg[Path],
+                   compileBridgeSources: Agg[Path],
                    compileClasspath: Agg[Path],
                    compilerClasspath: Agg[Path],
                    pluginClasspath: Agg[Path],
-                   compilerBridge: Path,
                    scalacOptions: Seq[String],
                    scalacPluginClasspath: Agg[Path],
                    javacOptions: Seq[String],
diff --git a/scalalib/test/src/mill/scalalib/ResolveDepsTests.scala b/scalalib/test/src/mill/scalalib/ResolveDepsTests.scala
index d1ddde20..f697127c 100644
--- a/scalalib/test/src/mill/scalalib/ResolveDepsTests.scala
+++ b/scalalib/test/src/mill/scalalib/ResolveDepsTests.scala
@@ -10,7 +10,7 @@ import utest._
 object ResolveDepsTests extends TestSuite {
   val repos = Seq(Cache.ivy2Local, MavenRepository("https://repo1.maven.org/maven2"))
 
-  def evalDeps(deps: Agg[Dep]): Result[Agg[PathRef]] = Lib.resolveDependencies(repos, "2.12.4", "2.12", deps)
+  def evalDeps(deps: Agg[Dep]): Result[Agg[PathRef]] = Lib.resolveDependencies(repos, "2.12.4", deps)
 
   val tests = Tests {
     'resolveValidDeps - {