1 files changed, 252 insertions, 0 deletions
diff --git a/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
new file mode 100644
index 00000000..6b21de84
--- /dev/null
+++ b/scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala
@@ -0,0 +1,252 @@
+package mill.scalalib.worker
+
+import java.io.File
+import java.util.Optional
+
+import ammonite.ops.{Path, exists, ls, mkdir}
+import ammonite.util.Colors
+import mill.Agg
+import mill.eval.PathRef
+import mill.scalalib.{CompilationResult, Lib, TestRunner}
+import xsbti.compile.{CompilerCache => _, FileAnalysisStore => _, ScalaInstance => _, _}
+import mill.scalalib.Dep.isDotty
+import mill.scalalib.Lib.{grepJar, scalaBinaryVersion}
+import mill.util.{Ctx, PrintLogger}
+import sbt.internal.inc._
+import sbt.internal.util.{ConsoleOut, MainAppender}
+import sbt.util.LogExchange
+
+case class MockedLookup(am: File => Optional[CompileAnalysis]) extends PerClasspathEntryLookup {
+  override def analysis(classpathEntry: File): Optional[CompileAnalysis] =
+    am(classpathEntry)
+
+  override def definesClass(classpathEntry: File): DefinesClass =
+    Locate.definesClass(classpathEntry)
+}
+
+class ZincWorkerImpl(ctx0: mill.util.Ctx,
+                     compilerBridgeClasspath: Array[String]) extends mill.scalalib.ZincWorkerApi{
+  private val ic = new sbt.internal.inc.IncrementalCompilerImpl()
+  val javaOnlyCompilers = {
+    // Keep the classpath as written by the user
+    val classpathOptions = ClasspathOptions.of(false, false, false, false, false)
+
+    val dummyFile = new java.io.File("")
+    // Zinc does not have an entry point for Java-only compilation, so we need
+    // to make up a dummy ScalaCompiler instance.
+    val scalac = ZincUtil.scalaCompiler(
+      new ScalaInstance("", null, null, dummyFile, dummyFile, new Array(0), Some("")), null,
+      classpathOptions // this is used for javac too
+    )
+
+    ic.compilers(
+      instance = null,
+      classpathOptions,
+      None,
+      scalac
+    )
+  }
+
+  @volatile var mixedCompilersCache = Option.empty[(Long, Compilers)]
+
+
+  /** Compile the bridge if it doesn't exist yet and return the output directory.
+   *  TODO: Proper invalidation, see #389
+   */
+  def compileZincBridgeIfNeeded(scalaVersion: String,
+                                sourcesJar: Path,
+                                compilerJars: Array[File]): Path = {
+    val workingDir = ctx0.dest / scalaVersion
+    val compiledDest = workingDir / 'compiled
+    if (!exists(workingDir)) {
+
+      ctx0.log.info("Compiling compiler interface...")
+
+      mkdir(workingDir)
+      mkdir(compiledDest)
+
+      val sourceFolder = mill.modules.Util.unpackZip(sourcesJar)(workingDir)
+      val classloader = mill.util.ClassLoader.create(compilerJars.map(_.toURI.toURL), null)(ctx0)
+      val compilerMain = classloader.loadClass(
+        if (isDotty(scalaVersion))
+          "dotty.tools.dotc.Main"
+        else
+          "scala.tools.nsc.Main"
+      )
+      val argsArray = Array[String](
+        "-d", compiledDest.toString,
+        "-classpath", (compilerJars ++ compilerBridgeClasspath).mkString(File.pathSeparator)
+      ) ++ ls.rec(sourceFolder.path).filter(_.ext == "scala").map(_.toString)
+
+      compilerMain.getMethod("process", classOf[Array[String]])
+        .invoke(null, argsArray)
+    }
+    compiledDest
+  }
+
+
+
+  def discoverMainClasses(compilationResult: CompilationResult)(implicit ctx: mill.util.Ctx): Seq[String] = {
+    def toScala[A](o: Optional[A]): Option[A] = if (o.isPresent) Some(o.get) else None
+
+    toScala(FileAnalysisStore.binary(compilationResult.analysisFile.toIO).get())
+      .map(_.getAnalysis)
+      .flatMap{
+        case analysis: Analysis =>
+          Some(analysis.infos.allInfos.values.map(_.getMainClasses).flatten.toSeq.sorted)
+        case _ =>
+          None
+      }
+      .getOrElse(Seq.empty[String])
+  }
+
+  def compileJava(upstreamCompileOutput: Seq[CompilationResult],
+                  sources: Agg[Path],
+                  compileClasspath: Agg[Path],
+                  javacOptions: Seq[String])
+                 (implicit ctx: mill.util.Ctx): mill.eval.Result[CompilationResult] = {
+    compileInternal(
+      upstreamCompileOutput,
+      sources,
+      compileClasspath,
+      javacOptions,
+      scalacOptions = Nil,
+      javaOnlyCompilers
+    )
+  }
+
+  def compileMixed(upstreamCompileOutput: Seq[CompilationResult],
+                   sources: Agg[Path],
+                   compileClasspath: Agg[Path],
+                   javacOptions: Seq[String],
+                   scalaVersion: String,
+                   scalacOptions: Seq[String],
+                   compilerBridgeSources: Path,
+                   compilerClasspath: Agg[Path],
+                   scalacPluginClasspath: Agg[Path])
+                  (implicit ctx: mill.util.Ctx): mill.eval.Result[CompilationResult] = {
+    val compilerJars = compilerClasspath.toArray.map(_.toIO)
+
+    val compilerBridge = compileZincBridgeIfNeeded(scalaVersion, compilerBridgeSources, compilerJars)
+    val compilerBridgeSig = compilerBridge.mtime.toMillis
+
+    val compilersSig = compilerBridgeSig + compilerClasspath.map(p => p.toString().hashCode + p.mtime.toMillis).sum
+    val compilers = mixedCompilersCache match {
+      case Some((k, v)) if k == compilersSig => v
+      case _ =>
+        val compilerName =
+          if (isDotty(scalaVersion))
+            s"dotty-compiler_${scalaBinaryVersion(scalaVersion)}"
+          else
+            "scala-compiler"
+        val scalaInstance = new ScalaInstance(
+          version = scalaVersion,
+          loader = mill.util.ClassLoader.create(compilerJars.map(_.toURI.toURL), null),
+          libraryJar = grepJar(compilerClasspath, "scala-library", scalaVersion).toIO,
+          compilerJar = grepJar(compilerClasspath, compilerName, scalaVersion).toIO,
+          allJars = compilerJars,
+          explicitActual = None
+        )
+        val compilers = ic.compilers(
+          scalaInstance,
+          ClasspathOptionsUtil.boot,
+          None,
+          ZincUtil.scalaCompiler(scalaInstance, compilerBridge.toIO)
+        )
+        mixedCompilersCache = Some((compilersSig, compilers))
+        compilers
+    }
+
+    compileInternal(
+      upstreamCompileOutput,
+      sources,
+      compileClasspath,
+      javacOptions,
+      scalacOptions = scalacPluginClasspath.map(jar => s"-Xplugin:${jar}").toSeq ++ scalacOptions,
+      compilers
+    )
+  }
+
+  private def compileInternal(upstreamCompileOutput: Seq[CompilationResult],
+                              sources: Agg[Path],
+                              compileClasspath: Agg[Path],
+                              javacOptions: Seq[String],
+                              scalacOptions: Seq[String],
+                              compilers: Compilers)
+                             (implicit ctx: mill.util.Ctx): mill.eval.Result[CompilationResult] = {
+    mkdir(ctx.dest)
+
+    val logger = {
+      val consoleAppender = MainAppender.defaultScreen(ConsoleOut.printStreamOut(
+        ctx.log.outputStream
+      ))
+      val l = LogExchange.logger("Hello")
+      LogExchange.unbindLoggerAppenders("Hello")
+      LogExchange.bindLoggerAppenders("Hello", (consoleAppender -> sbt.util.Level.Info) :: Nil)
+      l
+    }
+
+    def analysisMap(f: File): Optional[CompileAnalysis] = {
+      if (f.isFile) {
+        Optional.empty[CompileAnalysis]
+      } else {
+        upstreamCompileOutput.collectFirst {
+          case CompilationResult(zincPath, classFiles) if classFiles.path.toNIO == f.toPath =>
+            FileAnalysisStore.binary(zincPath.toIO).get().map[CompileAnalysis](_.getAnalysis)
+        }.getOrElse(Optional.empty[CompileAnalysis])
+      }
+    }
+
+    val lookup = MockedLookup(analysisMap)
+
+    val zincFile = ctx.dest / 'zinc
+    val classesDir = ctx.dest / 'classes
+
+    val zincIOFile = zincFile.toIO
+    val classesIODir = classesDir.toIO
+
+    val store = FileAnalysisStore.binary(zincIOFile)
+
+    val inputs = ic.inputs(
+      classpath = classesIODir +: compileClasspath.map(_.toIO).toArray,
+      sources = sources.toArray.map(_.toIO),
+      classesDirectory = classesIODir,
+      scalacOptions = scalacOptions.toArray,
+      javacOptions = javacOptions.toArray,
+      maxErrors = 10,
+      sourcePositionMappers = Array(),
+      order = CompileOrder.Mixed,
+      compilers = compilers,
+      setup = ic.setup(
+        lookup,
+        skip = false,
+        zincIOFile,
+        new FreshCompilerCache,
+        IncOptions.of(),
+        new ManagedLoggedReporter(10, logger),
+        None,
+        Array()
+      ),
+      pr = {
+        val prev = store.get()
+        PreviousResult.of(prev.map(_.getAnalysis), prev.map(_.getMiniSetup))
+      }
+    )
+
+    try {
+      val newResult = ic.compile(
+        in = inputs,
+        logger = logger
+      )
+
+      store.set(
+        AnalysisContents.create(
+          newResult.analysis(),
+          newResult.setup()
+        )
+      )
+
+      mill.eval.Result.Success(CompilationResult(zincFile, PathRef(classesDir)))
+    }catch{case e: CompileFailed => mill.eval.Result.Failure(e.toString)}
+  }
+}