Support doc task with dottydoc

project/Build.scala

@@ -289,10 +289,14 @@ object Build {
         compilerJar = jars.find(_.getName.startsWith("dotty-compiler_2.12")).get
       }
 
-      // All compiler dependencies except the library
-      val otherDependencies = dependencyClasspath.in(`dotty-compiler`, Compile).value
-        .filterNot(_.get(artifact.key).exists(_.name == "dotty-library"))
-        .map(_.data)
+      // All dotty-doc's and compiler's dependencies except the library.
+      // (we get the compiler's dependencies because dottydoc depends on the compiler)
+      val otherDependencies = {
+        val excluded = Set("dotty-library", "dotty-compiler")
+        fullClasspath.in(`dotty-doc`, Compile).value
+          .filterNot(_.get(artifact.key).exists(a => excluded.contains(a.name)))
+          .map(_.data)
+      }
 
       val allJars = libraryJar :: compilerJar :: otherDependencies.toList
       val classLoader = state.value.classLoaderCache(allJars)
@@ -785,7 +789,7 @@ object Build {
     description := "sbt compiler bridge for Dotty",
     resolvers += Resolver.typesafeIvyRepo("releases"), // For org.scala-sbt:api
     libraryDependencies ++= Seq(
-      Dependencies.compilerInterface(sbtVersion.value),
+      Dependencies.compilerInterface(sbtVersion.value) % Provided,
       (Dependencies.zincApiinfo(sbtVersion.value) % Test).withDottyCompat(scalaVersion.value)
     ),
     // The sources should be published with crossPaths := false since they
@@ -1269,6 +1273,7 @@ object Build {
     def asDottySbtBridge(implicit mode: Mode): Project = project.withCommonSettings.
       disablePlugins(ScriptedPlugin).
       dependsOn(dottyCompiler % Provided).
+      dependsOn(dottyDoc % Provided).
       settings(dottySbtBridgeSettings)
 
     def asDottyBench(implicit mode: Mode): Project = project.withCommonSettings.

sbt-bridge/src/xsbt/ScaladocInterface.scala

@@ -7,57 +7,27 @@ import xsbti.{ Logger, Severity }
 import java.net.URL
 import java.util.Optional
 
+import dotty.tools.dotc.core.Contexts.{ Context, ContextBase }
+import dotty.tools.dotc.reporting.Reporter
+
 class ScaladocInterface {
-  def run(args: Array[String], log: Logger, delegate: xsbti.Reporter) =
-    (new DottydocRunner(args, log, delegate)).run()
+  def run(args: Array[String], log: Logger, delegate: xsbti.Reporter) = {
+    new DottydocRunner(args, log, delegate).run()
+  }
 }
 
 class DottydocRunner(args: Array[String], log: Logger, delegate: xsbti.Reporter) {
-  def run(): Unit = delegate.log(Problem(
-    NoPosition,
-    """|The dotty sbt-bridge currently does not support doc generation directly
-       |via sbt. Please see the dotty documentation at dotty.epfl.ch""".stripMargin,
-    Severity.Error
-  ))
-
-  private[this] val NoPosition = new xsbti.Position {
-    val line = Optional.empty[Integer]
-    val lineContent = ""
-    val offset = Optional.empty[Integer]
-    val sourcePath = Optional.empty[String]
-    val sourceFile = Optional.empty[java.io.File]
-    val pointer = Optional.empty[Integer]
-    val pointerSpace = Optional.empty[String]
-  }
-
-  private def getStringSetting(name: String): Option[String] =
-    args find (_.startsWith(name)) map (_.drop(name.length))
-
-  private def getOutputFolder(args: Array[String]): Option[String] =
-    args sliding(2) find { case Array(x, _) => x == "-d" } map (_.tail.head.trim)
-
-  private def getTemplate(resources: List[URL]): Option[URL] =
-    resources.find(_.getFile.endsWith("template.html"))
-
-  private def getResources(args: Array[String]): List[URL] = {
-    val cp = args sliding (2) find { case Array(x, _) => x == "-classpath" } map (_.tail.head.trim) getOrElse ""
-
-    cp.split(":").find(_.endsWith("dottydoc-client.jar")).map { resourceJar =>
-      import java.util.jar.JarFile
-      val jarEntries = (new JarFile(resourceJar)).entries
-      var entries: List[URL] = Nil
-
-      while (jarEntries.hasMoreElements) {
-        val entry = jarEntries.nextElement()
-
-        if (!entry.isDirectory()) {
-          val path = s"jar:file:$resourceJar!/${entry.getName}"
-          val url  = new URL(path)
-          entries = url :: entries
-        }
-      }
-
-      entries
-    } getOrElse (Nil)
+  def run(): Unit = {
+    log.debug(() => args.mkString("Calling Dottydoc with arguments  (ScaladocInterface):\n\t", "\n\t", ""))
+
+    val ctx = (new ContextBase).initialCtx.fresh
+      .setReporter(new DelegatingReporter(delegate))
+
+    val dottydocMainClass = Class.forName("dotty.tools.dottydoc.Main")
+    val processMethod = dottydocMainClass.getMethod("process", classOf[Array[String]], classOf[Context])
+    val reporter = processMethod.invoke(null, args, ctx).asInstanceOf[Reporter]
+    if (reporter.hasErrors) {
+      throw new InterfaceCompileFailed(args, Array())
+    }
   }
 }

sbt-dotty/sbt-test/sbt-dotty/example-project/src/main/scala/hello/Hello.scala

@@ -1,4 +1,5 @@
 package hello
+/** Hello, world! */
 object Hello {
   def main(args: Array[String]): Unit = {
     val dotty: Int | String = "dotty"

sbt-dotty/sbt-test/sbt-dotty/example-project/test

@@ -1,4 +1,5 @@
 > run
+> doc
 > 'set initialCommands := "1 + 1" '
 # FIXME: does not work on the CI
 #> console

sbt-dotty/src/dotty/tools/sbtplugin/DottyPlugin.scala

@@ -2,8 +2,10 @@ package dotty.tools.sbtplugin
 
 import sbt._
 import sbt.Keys._
-// import sbt.inc.{ ClassfileManager, IncOptions }
+import sbt.librarymanagement.DependencyResolution
+import sbt.internal.inc.ScalaInstance
 import xsbti.compile._
+import java.net.URLClassLoader
 import java.util.Optional
 
 object DottyPlugin extends AutoPlugin {
@@ -151,6 +153,8 @@ object DottyPlugin extends AutoPlugin {
           scalaOrganization.value
       },
 
+      scalacOptions in (Compile, doc) ++= Seq("-project", name.value),
+
       incOptions in Compile := {
         val inc = (incOptions in Compile).value
         if (isDotty.value)
@@ -174,7 +178,43 @@ object DottyPlugin extends AutoPlugin {
           scalaVersion.value.split("\\.").take(2).mkString(".")
         else
           scalaBinaryVersion.value
-      }
+      },
+
+      scalaInstance := Def.taskDyn {
+        val si = scalaInstance.value
+        if (isDotty.value) {
+          Def.task {
+            val dottydocArtifacts = fetchArtifactsOf("dotty-doc").value
+            val includeArtifact = (f: File) => f.getName.endsWith(".jar")
+            val dottydocJars = dottydocArtifacts.filter(includeArtifact).toArray
+            val allJars = (si.allJars ++ dottydocJars).distinct
+            val loader = new URLClassLoader(Path.toURLs(dottydocJars), si.loader)
+            new ScalaInstance(si.version, loader, si.loaderLibraryOnly, si.libraryJar, si.compilerJar, allJars, si.explicitActual)
+          }
+        } else {
+          Def.task { si }
+        }
+      }.value
     )
   }
+
+  /** Fetch artefacts for scalaOrganization.value %% moduleName % scalaVersion.value */
+  private def fetchArtifactsOf(moduleName: String) = Def.task {
+    val dependencyResolution = Keys.dependencyResolution.value
+    val log = streams.value.log
+    val scalaInfo = scalaModuleInfo.value
+    val updateConfiguration = Keys.updateConfiguration.value
+    val warningConfiguration = (unresolvedWarningConfiguration in update).value
+
+    val moduleID = (scalaOrganization.value %% moduleName % scalaVersion.value).cross(CrossVersion.binary)
+    val descriptor = dependencyResolution.wrapDependencyInModule(moduleID, scalaInfo)
+
+    dependencyResolution.update(descriptor, updateConfiguration, warningConfiguration, log) match {
+      case Right(report) =>
+        report.allFiles
+      case _ =>
+        throw new MessageOnlyException(
+          s"Couldn't retrieve `${scalaOrganization.value} %% $moduleName %% ${scalaVersion.value}`.")
+    }
+  }
 }