BSP: Improve support for mill-build module and the build.sc

bsp/worker/src/mill/bsp/worker/MillBuildServer.scala

@@ -62,8 +62,9 @@ import mill.define.{BaseModule, Discover, ExternalModule, Module, Segments, Task
 import mill.eval.Evaluator
 import mill.main.{BspServerResult, EvaluatorScopt, MainModule}
 import mill.scalalib.{JavaModule, SemanticDbJavaModule, TestModule}
-import mill.scalalib.bsp.{BspModule, JvmBuildTarget, MillBuildTarget, ScalaBuildTarget}
+import mill.scalalib.bsp.{BspModule, JvmBuildTarget, MillBuildModule, ScalaBuildTarget}
 import mill.scalalib.internal.ModuleUtils
+import os.Path
 
 import java.io.PrintStream
 import java.util.concurrent.CompletableFuture
@@ -105,7 +106,7 @@ class MillBuildServer(
             val modules: Seq[Module] =
               ModuleUtils.transitiveModules(evaluator.rootModule) ++ Seq(`mill-build`)
             val map = modules.collect {
-              case m: MillBuildTarget =>
+              case m: MillBuildModule =>
                 val uri = sanitizeUri(m.millSourcePath) +
                   m.bspBuildTarget.displayName.map(n => s"?id=${n}").getOrElse("")
                 val id = new BuildTargetIdentifier(uri)
@@ -129,9 +130,9 @@ class MillBuildServer(
 
     }
 
-    lazy val `mill-build`: MillBuildTarget = {
-      object `mill-build` extends MillBuildTarget {
-        override protected def rootModule: BaseModule = evaluator.rootModule
+    lazy val `mill-build`: MillBuildModule = {
+      object `mill-build` extends MillBuildModule {
+        override protected def projectPath: Path = evaluator.rootModule.millSourcePath
       }
       `mill-build`
     }
@@ -154,8 +155,6 @@ class MillBuildServer(
   private[this] var statePromise: Promise[State] = Promise[State]()
   initialEvaluator.foreach(e => statePromise.success(new State(e)))
 
-//  private[this] def stateFuture: Future[State] = statePromise.future
-
   def updateEvaluator(evaluator: Option[Evaluator]): Unit = {
     log.debug(s"Updating Evaluator: ${evaluator}")
     if (statePromise.isCompleted) {
@@ -374,7 +373,7 @@ class MillBuildServer(
         targetIds = sourcesParams.getTargets.asScala.toSeq,
         agg = (items: Seq[SourcesItem]) => new SourcesResult(items.asJava)
       ) {
-        case (id, module: MillBuildTarget) if clientIsIntelliJ =>
+        case (id, module: MillBuildModule) if clientIsIntelliJ =>
           T.task {
             val sources = new SourcesItem(
               id,
@@ -733,28 +732,29 @@ class MillBuildServer(
   )(f: State => V): CompletableFuture[V] = {
     log.debug(s"Entered ${hint}")
     val start = System.currentTimeMillis()
+    val prefix = hint.split(" ").head
     def took =
-      log.debug(s"${hint.split("[ ]").head} took ${System.currentTimeMillis() - start} msec")
+      log.debug(s"${prefix} took ${System.currentTimeMillis() - start} msec")
 
     val future = new CompletableFuture[V]()
 
     if (checkInitialized && !initialized) {
       future.completeExceptionally(
-        new Exception("Can not respond to any request before receiving the `initialize` request.")
+        new Exception(s"Can not respond to ${prefix} request before receiving the `initialize` request.")
       )
     } else {
       statePromise.future.onComplete {
         case Success(state) =>
           try {
             val v = f(state)
-            log.debug(s"${hint.split("[ ]").head} result: ${v}")
             took
+            log.debug(s"${prefix} result: ${v}")
             future.complete(v)
           } catch {
             case e: Exception =>
-              logStream.println(s"Caught exception: ${e}")
-              e.printStackTrace(logStream)
               took
+              logStream.println(s"${prefix} caught exception: ${e}")
+              e.printStackTrace(logStream)
               future.completeExceptionally(e)
           }
         case Failure(exception) =>
@@ -772,26 +772,27 @@ class MillBuildServer(
   )(f: => V): CompletableFuture[V] = {
     log.debug(s"Entered ${hint}")
     val start = System.currentTimeMillis()
+    val prefix = hint.split(" ").head
     def took =
-      log.debug(s"${hint.split("[ ]").head} took ${System.currentTimeMillis() - start} msec")
+      log.debug(s"${prefix} took ${System.currentTimeMillis() - start} msec")
 
     val future = new CompletableFuture[V]()
 
     if (checkInitialized && !initialized) {
       future.completeExceptionally(
-        new Exception("Can not respond to any request before receiving the `initialize` request.")
+        new Exception(s"Can not respond to ${prefix} request before receiving the `initialize` request.")
       )
     } else {
       try {
         val v = f
-        log.debug(s"${hint.split("[ ]").head} result: ${v}")
         took
+        log.debug(s"${prefix} result: ${v}")
         future.complete(v)
       } catch {
         case e: Exception =>
-          logStream.println(s"Caugh exception: ${e}")
-          e.printStackTrace(logStream)
           took
+          logStream.println(s"${prefix} caught exception: ${e}")
+          e.printStackTrace(logStream)
           future.completeExceptionally(e)
       }
     }

bsp/worker/src/mill/bsp/worker/MillJavaBuildServer.scala

@@ -10,6 +10,7 @@ import scala.jdk.CollectionConverters._
 
 @internal
 trait MillJavaBuildServer extends JavaBuildServer { this: MillBuildServer =>
+
   override def buildTargetJavacOptions(javacOptionsParams: JavacOptionsParams)
       : CompletableFuture[JavacOptionsResult] =
     completable(s"buildTargetJavacOptions ${javacOptionsParams}") { state =>

build.sc

@@ -148,7 +148,8 @@ object Deps {
   val log4j2Core = ivy"org.apache.logging.log4j:log4j-core:2.19.0"
   val osLib = ivy"com.lihaoyi::os-lib:0.9.0"
   val millModuledefsVersion = "0.10.9"
-  val millModuledefs = ivy"com.lihaoyi::mill-moduledefs:${millModuledefsVersion}"
+  val millModuledefsString = s"com.lihaoyi::mill-moduledefs:${millModuledefsVersion}"
+  val millModuledefs = ivy"${millModuledefsString}"
   val millModuledefsPlugin =
     ivy"com.lihaoyi:::scalac-mill-moduledefs-plugin:${millModuledefsVersion}"
   val testng = ivy"org.testng:testng:7.5"
@@ -418,6 +419,10 @@ object main extends MillModule {
            |  val millEmbeddedDeps = ${artifacts.map(artifact =>
             s""""${artifact.group}:${artifact.id}:${artifact.version}""""
           )}
+           |  /** Scalac compiler plugin dependencies to compile the build script. */
+           |  val millScalacPluginDeps = Seq(
+           |    "${Deps.millModuledefsString}"
+           |  )
            |  /** Mill documentation url. */
            |  val millDocUrl = "${Settings.docUrl}"
            |}

scalalib/src/mill/scalalib/SemanticDbJavaModule.scala

@@ -224,7 +224,7 @@ trait SemanticDbJavaModule extends CoursierModule { hostModule: JavaModule =>
   }
 
   // keep in sync with bspCompiledClassesAndSemanticDbFiles
-  def compiledClassesAndSemanticDbFiles = T {
+  def compiledClassesAndSemanticDbFiles: Target[PathRef] = T {
     val dest = T.dest
     val classes = compile().classes.path
     val sems = semanticDbData().path
@@ -236,7 +236,7 @@ trait SemanticDbJavaModule extends CoursierModule { hostModule: JavaModule =>
   // keep in sync with compiledClassesAndSemanticDbFiles
   def bspCompiledClassesAndSemanticDbFiles: Target[UnresolvedPath] = {
     if (
-      compile.ctx.enclosing == s"${classOf[SemanticDbJavaModule].getName}#compiledClassesAndSemanticDbFiles"
+      compiledClassesAndSemanticDbFiles.ctx.enclosing == s"${classOf[SemanticDbJavaModule].getName}#compiledClassesAndSemanticDbFiles"
     ) {
       T {
         T.log.debug(

scalalib/src/mill/scalalib/bsp/BspBuildTarget.scala

@@ -0,0 +1,12 @@
+package mill.scalalib.bsp
+
+case class BspBuildTarget(
+    displayName: Option[String],
+    baseDirectory: Option[os.Path],
+    tags: Seq[String],
+    languageIds: Seq[String],
+    canCompile: Boolean,
+    canTest: Boolean,
+    canRun: Boolean,
+    canDebug: Boolean
+)

scalalib/src/mill/scalalib/bsp/BspModule.scala

@@ -26,18 +26,26 @@ trait BspModule extends Module {
     canDebug = false
   )
 
-  /** Use to populate the `BuildTarget.{dataKind,data}` fields. */
+  /**
+   * Use to populate the `BuildTarget.{dataKind,data}` fields.
+   *
+   * Mill specific implementations:
+   * - [[JvmBuildTarget]]
+   * - [[ScalaBuildTarget]]
+   */
   @internal
   def bspBuildTargetData: Task[Option[(String, AnyRef)]] = T.task { None }
 
 }
 
 object BspModule {
+  /** Used to define the [[BspBuildTarget.languageIds]] field. */
   object LanguageId {
     val Java = "java"
     val Scala = "scala"
   }
 
+  /** Used to define the [[BspBuildTarget.tags]] field. */
   object Tag {
     val Library = "library"
     val Application = "application"
@@ -48,142 +56,3 @@ object BspModule {
     val Manual = "manual"
   }
 }
-
-case class BspBuildTarget(
-    displayName: Option[String],
-    baseDirectory: Option[os.Path],
-    tags: Seq[String],
-    languageIds: Seq[String],
-    canCompile: Boolean,
-    canTest: Boolean,
-    canRun: Boolean,
-    canDebug: Boolean
-)
-
-case class BspBuildTargetId(id: BspUri)
-
-case class BspUri(uri: String)
-
-object BspUri {
-  def apply(path: os.Path): BspUri = BspUri(path.toNIO.toUri.toString)
-}
-
-case class JvmBuildTarget(
-    javaHome: Option[BspUri],
-    javaVersion: Option[String]
-)
-
-object JvmBuildTarget {
-  val dataKind: String = "jvm"
-}
-
-case class ScalaBuildTarget(
-    /** The Scala organization that is used for a target. */
-    scalaOrganization: String,
-    /** The scala version to compile this target */
-    scalaVersion: String,
-    /**
-     * The binary version of scalaVersion.
-     * For example, 2.12 if scalaVersion is 2.12.4.
-     */
-    scalaBinaryVersion: String,
-    /** The target platform for this target */
-    platform: ScalaPlatform,
-    /** A sequence of Scala jars such as scala-library, scala-compiler and scala-reflect. */
-    jars: Seq[String],
-    /** The jvm build target describing jdk to be used */
-    jvmBuildTarget: Option[JvmBuildTarget]
-)
-
-object ScalaBuildTarget {
-  val dataKind: String = "scala"
-}
-
-abstract class ScalaPlatform(val number: Int)
-object ScalaPlatform {
-  case object JVM extends ScalaPlatform(1)
-  case object JS extends ScalaPlatform(2)
-  case object Native extends ScalaPlatform(3)
-}
-
-/**
- * Synthetic module representing the mill-build project itself in a BSP context.
- * @param rootModule
- * @param outerCtx0
- */
-@internal
-trait MillBuildTarget
-    extends ScalaModule {
-  protected def rootModule: BaseModule
-  override def millSourcePath: os.Path = rootModule.millSourcePath
-  override def scalaVersion: T[String] = BuildInfo.scalaVersion
-  override def compileIvyDeps: T[Agg[Dep]] = T {
-    T.log.errorStream.println(s"ivyDeps: ${T.dest}")
-    Agg.from(BuildInfo.millEmbeddedDeps.map(d => ivy"${d}"))
-  }
-
-  /**
-   * We need to add all resources from Ammonites cache,
-   * which typically also include resolved `ivy`-imports and compiled `$file`-imports.
-   */
-  override def unmanagedClasspath: T[Agg[PathRef]] = T {
-    super.unmanagedClasspath() ++ (
-      rootModule.getClass.getClassLoader match {
-        case cl: SpecialClassLoader =>
-          cl.allJars.map(url => PathRef(os.Path(java.nio.file.Paths.get(url.toURI))))
-        case _ => Seq()
-      }
-    )
-  }
-
-  // The buildfile and single source of truth
-  def buildScFile = T.source(millSourcePath / "build.sc")
-  def ammoniteFiles = T {
-    T.log.errorStream.println(s"ammoniteFiles: ${T.dest}")
-    // we depend on buildScFile, to recompute whenever build.sc changes
-    findSources(Seq(millSourcePath), excludes = Seq(millSourcePath / "out"))
-  }
-  // We need to be careful here to not include the out/ directory
-  override def sources: Sources = T.sources {
-    T.log.errorStream.println(s"sources: ${T.dest}")
-    val sources = ammoniteFiles()
-    T.log.errorStream.println(s"sources: ${sources}")
-    sources
-  }
-  override def allSourceFiles: T[Seq[PathRef]] = T {
-    findSources(sources().map(_.path))
-  }
-  def findSources(paths: Seq[os.Path], excludes: Seq[os.Path] = Seq()): Seq[PathRef] = {
-    def isHiddenFile(path: os.Path) = path.last.startsWith(".")
-    (for {
-      root <- paths
-      if os.exists(root) && !excludes.exists(excl => root.startsWith(excl))
-      path <- if (os.isDir(root)) os.walk(root) else Seq(root)
-      if os.isFile(path) && ((path.ext == "sc") && !isHiddenFile(path))
-    } yield PathRef(path)).distinct
-  }
-  override def bspBuildTarget: BspBuildTarget = super.bspBuildTarget.copy(
-    displayName = Some("mill-build"),
-    baseDirectory = Some(rootModule.millSourcePath),
-    languageIds = Seq(BspModule.LanguageId.Scala),
-    canRun = false,
-    canCompile = false,
-    canTest = false,
-    canDebug = false,
-    tags = Seq(BspModule.Tag.Library, BspModule.Tag.Application)
-  )
-  override def compile: T[CompilationResult] = T {
-    T.log.errorStream.println(s"compile: ${T.dest}")
-    os.write(T.dest / "dummy", "")
-    os.makeDir(T.dest / "classes")
-    CompilationResult(T.dest / "dummy", PathRef(T.dest / "classes"))
-  }
-
-  override def semanticDbData: T[PathRef] = T {
-    T.log.errorStream.println(s"semanticDbData: ${T.dest}")
-    PathRef(T.dest)
-  }
-
-  /** Used in BSP IntelliJ, which can only work with directories */
-  def dummySources: Sources = T.sources(T.dest)
-}

scalalib/src/mill/scalalib/bsp/BspUri.scala

@@ -0,0 +1,7 @@
+package mill.scalalib.bsp
+
+case class BspUri(uri: String)
+
+object BspUri {
+  def apply(path: os.Path): BspUri = BspUri(path.toNIO.toUri.toString)
+}