Merge pull request #47 from eed3si9n/topic/library-loader

Layered class loading of library and compiler
sbt · Mar 5, 2018 · 200eeff · 200eeff
2 parents a17567c + d8d79b7
commit 200eeff
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Showing 5 changed files with 51 additions and 7 deletions.
diff --git a/launcher-implementation/src/main/scala/xsbt/boot/Launch.scala b/launcher-implementation/src/main/scala/xsbt/boot/Launch.scala
@@ -322,11 +322,18 @@ class Launch private[xsbt] (val bootDirectory: File, val lockBoot: Boolean, val
     }
   def componentProvider(appHome: File) = new ComponentProvider(appHome, lockBoot)
 
-  def scalaProvider(scalaVersion: String, module: RetrievedModule, parentLoader: ClassLoader, scalaLibDir: File): xsbti.ScalaProvider = new xsbti.ScalaProvider {
+  def scalaProvider(scalaVersion: String, module: RetrievedModule, parentLoader: ClassLoader, scalaLibDir: File): xsbti.ScalaProvider = new xsbti.ExtendedScalaProvider {
     def launcher = Launch.this
     def version = scalaVersion
-    lazy val loader = module.createLoader(parentLoader)
 
+    private object LoaderInit {
+      val (library, other) = module.fullClasspath.partition(_.getName.startsWith("scala-library"))
+      val libraryLoader = new LibraryClassLoader(toURLs(library), parentLoader, scalaVersion)
+      val fullLoader = new URLClassLoader(toURLs(other), libraryLoader)
+    }
+
+    override def loaderLibraryOnly(): ClassLoader = LoaderInit.libraryLoader
+    override def loader(): ClassLoader = LoaderInit.fullLoader
     def compilerJar = new File(scalaLibDir, CompilerModuleName + ".jar")
     def libraryJar = new File(scalaLibDir, LibraryModuleName + ".jar")
     def jars = module.fullClasspath

diff --git a/launcher-implementation/src/main/scala/xsbt/boot/LibraryClassLoader.scala b/launcher-implementation/src/main/scala/xsbt/boot/LibraryClassLoader.scala
@@ -0,0 +1,7 @@
+package xsbt.boot
+
+import java.net.{ URL, URLClassLoader }
+
+final class LibraryClassLoader(urls: Array[URL], parent: ClassLoader,
+  val scalaVersion: String) extends URLClassLoader(urls, parent) with xsbti.LibraryClassLoader {
+}
diff --git a/launcher-implementation/src/test/scala/ScalaProviderTest.scala b/launcher-implementation/src/test/scala/ScalaProviderTest.scala
@@ -15,8 +15,10 @@ object ScalaProviderTest extends Specification {
     "provide ClassLoader for Scala 2.8.2" in { checkScalaLoader("2.8.2") }
     "provide ClassLoader for Scala 2.9.0" in { checkScalaLoader("2.9.0") }
     "provide ClassLoader for Scala 2.9.2" in { checkScalaLoader("2.9.2") }
-    "provide ClassLoader for Scala 2.10.4" in { checkScalaLoader("2.10.4") }
-    "provide ClassLoader for Scala 2.11.0" in { checkScalaLoader("2.11.0") }
+    "provide ClassLoader for Scala 2.10.7" in { checkScalaLoader("2.10.7") }
+    "provide ClassLoader for Scala 2.11.12" in { checkScalaLoader("2.11.12") }
+    // This requires the test to run in JDK 8
+    // "provide ClassLoader for Scala 2.12.4" in { checkScalaLoader("2.12.4") }
   }
 
   "Launch" should {
@@ -68,16 +70,26 @@ object ScalaProviderTest extends Specification {
       val provider = launcher.getScala(version)
       val loader = provider.loader
       // ensure that this loader can load Scala classes by trying scala.ScalaObject.
-      tryScala(loader)
+      tryScala(loader, loader.getParent)
       getScalaVersion(loader) must beEqualTo(versionValue)
+
+      val libraryLoader = provider.loader.getParent
+      // Test the structural type
+      libraryLoader match {
+        case x: ClassLoader with LibraryLoader => x.scalaVersion must be(version)
+      }
+      tryScala(libraryLoader, libraryLoader)
     }
-  private def tryScala(loader: ClassLoader) = Class.forName("scala.Product", false, loader).getClassLoader must be(loader)
+  private def tryScala(loader: ClassLoader, libraryLoader: ClassLoader) =
+    Class.forName("scala.Product", false, loader).getClassLoader must be(libraryLoader)
+
+  type LibraryLoader = { def scalaVersion: String }
 }
 object LaunchTest {
   def testApp(main: String): Application = testApp(main, Array[File]())
   def testApp(main: String, extra: Array[File]): Application = Application("org.scala-sbt", "launch-test", new Explicit(AppVersion), main, Nil, CrossValue.Disabled, extra)
   import Predefined._
-  def testRepositories = List(Local, ScalaToolsReleases, ScalaToolsSnapshots).map(Repository.Predefined(_))
+  def testRepositories = List(Local, MavenCentral, SonatypeOSSSnapshots).map(Repository.Predefined(_))
   def withLauncher[T](f: xsbti.Launcher => T): T =
     withTemporaryDirectory { bootDirectory =>
       f(Launcher(bootDirectory, testRepositories))

diff --git a/launcher-interface/src/main/java/xsbti/ExtendedScalaProvider.java b/launcher-interface/src/main/java/xsbti/ExtendedScalaProvider.java
@@ -0,0 +1,7 @@
+package xsbti;
+
+public interface ExtendedScalaProvider extends ScalaProvider
+{
+	/** A ClassLoader that loads the classes from scala-library.jar. It will be the parent of `loader` .*/
+	public ClassLoader loaderLibraryOnly();
+}
diff --git a/launcher-interface/src/main/java/xsbti/LibraryClassLoader.java b/launcher-interface/src/main/java/xsbti/LibraryClassLoader.java
@@ -0,0 +1,11 @@
+package xsbti;
+
+import java.io.File;
+
+/**
+ * Marker interface for classloader with just scala-library.
+ */
+public interface LibraryClassLoader
+{
+  public String scalaVersion();
+}