Merge pull request scala#4030 from som-snytt/issue/8843

SI-8843 AbsFileCL acts like a CL

Author: gkossakowski

src/reflect/scala/reflect/internal/util/AbstractFileClassLoader.scala

@@ -5,24 +5,24 @@
 package scala
 package reflect.internal.util
 
-import scala.reflect.io.AbstractFile
+import scala.collection.{ mutable, immutable }
+import scala.reflect.io.{ AbstractFile, Streamable }
+import java.net.{ URL, URLConnection, URLStreamHandler }
 import java.security.cert.Certificate
 import java.security.{ ProtectionDomain, CodeSource }
-import java.net.{ URL, URLConnection, URLStreamHandler }
-import scala.collection.{ mutable, immutable }
+import java.util.{ Collections => JCollections, Enumeration => JEnumeration }
 
-/**
- * A class loader that loads files from a {@link scala.tools.nsc.io.AbstractFile}.
+/** A class loader that loads files from a {@link scala.tools.nsc.io.AbstractFile}.
  *
- * @author Lex Spoon
+ *  @author Lex Spoon
  */
 class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader)
     extends ClassLoader(parent)
     with ScalaClassLoader
 {
   protected def classNameToPath(name: String): String =
     if (name endsWith ".class") name
-    else name.replace('.', '/') + ".class"
+    else s"${name.replace('.', '/')}.class"
 
   protected def findAbstractFile(name: String): AbstractFile = {
     var file: AbstractFile = root
@@ -56,35 +56,25 @@ class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader)
     file
   }
 
-  // parent delegation in JCL uses getResource; so either add parent.getResAsStream
-  // or implement findResource, which we do here as a study in scarlet (my complexion
-  // after looking at CLs and URLs)
-  override def findResource(name: String): URL = findAbstractFile(name) match {
+  override protected def findClass(name: String): Class[_] = {
+    val bytes = classBytes(name)
+    if (bytes.length == 0)
+      throw new ClassNotFoundException(name)
+    else
+      defineClass(name, bytes, 0, bytes.length, protectionDomain)
+  }
+  override protected def findResource(name: String): URL = findAbstractFile(name) match {
     case null => null
-    case file => new URL(null, "repldir:" + file.path, new URLStreamHandler {
+    case file => new URL(null, s"memory:${file.path}", new URLStreamHandler {
       override def openConnection(url: URL): URLConnection = new URLConnection(url) {
-        override def connect() { }
+        override def connect() = ()
         override def getInputStream = file.input
       }
     })
   }
-
-  // this inverts delegation order: super.getResAsStr calls parent.getRes if we fail
-  override def getResourceAsStream(name: String) = findAbstractFile(name) match {
-    case null => super.getResourceAsStream(name)
-    case file => file.input
-  }
-  // ScalaClassLoader.classBytes uses getResAsStream, so we'll try again before delegating
-  override def classBytes(name: String): Array[Byte] = findAbstractFile(classNameToPath(name)) match {
-    case null => super.classBytes(name)
-    case file => file.toByteArray
-  }
-  override def findClass(name: String): Class[_] = {
-    val bytes = classBytes(name)
-    if (bytes.length == 0)
-      throw new ClassNotFoundException(name)
-    else
-      defineClass(name, bytes, 0, bytes.length, protectionDomain)
+  override protected def findResources(name: String): JEnumeration[URL] = findResource(name) match {
+    case null => JCollections.enumeration(JCollections.emptyList[URL])  //JCollections.emptyEnumeration[URL]
+    case url  => JCollections.enumeration(JCollections.singleton(url))
   }
 
   lazy val protectionDomain = {
@@ -106,15 +96,13 @@ class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader)
     throw new UnsupportedOperationException()
   }
 
-  override def getPackage(name: String): Package = {
-    findAbstractDir(name) match {
-      case null => super.getPackage(name)
-      case file => packages.getOrElseUpdate(name, {
-        val ctor = classOf[Package].getDeclaredConstructor(classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[URL], classOf[ClassLoader])
-        ctor.setAccessible(true)
-        ctor.newInstance(name, null, null, null, null, null, null, null, this)
-      })
-    }
+  override def getPackage(name: String): Package = findAbstractDir(name) match {
+    case null => super.getPackage(name)
+    case file => packages.getOrElseUpdate(name, {
+      val ctor = classOf[Package].getDeclaredConstructor(classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[String], classOf[URL], classOf[ClassLoader])
+      ctor.setAccessible(true)
+      ctor.newInstance(name, null, null, null, null, null, null, null, this)
+    })
   }
 
   override def getPackages(): Array[Package] =

src/reflect/scala/reflect/internal/util/ScalaClassLoader.scala

@@ -53,8 +53,10 @@ trait ScalaClassLoader extends JClassLoader {
   }
 
   /** An InputStream representing the given class name, or null if not found. */
-  def classAsStream(className: String) =
-    getResourceAsStream(className.replaceAll("""\.""", "/") + ".class")
+  def classAsStream(className: String) = getResourceAsStream {
+    if (className endsWith ".class") className
+    else s"${className.replace('.', '/')}.class"  // classNameToPath
+  }
 
   /** Run the main method of a class to be loaded by this classloader */
   def run(objectName: String, arguments: Seq[String]) {

src/repl/scala/tools/nsc/interpreter/IMain.scala

@@ -295,22 +295,38 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
   def originalPath(name: Name): String   = typerOp path name
   def originalPath(sym: Symbol): String  = typerOp path sym
   def flatPath(sym: Symbol): String      = flatOp shift sym.javaClassName
+
   def translatePath(path: String) = {
     val sym = if (path endsWith "$") symbolOfTerm(path.init) else symbolOfIdent(path)
     sym.toOption map flatPath
   }
+
+  /** If path represents a class resource in the default package,
+   *  see if the corresponding symbol has a class file that is a REPL artifact
+   *  residing at a different resource path. Translate X.class to $line3/$read$$iw$$iw$X.class.
+   */
+  def translateSimpleResource(path: String): Option[String] = {
+    if (!(path contains '/') && (path endsWith ".class")) {
+      val name = path stripSuffix ".class"
+      val sym = if (name endsWith "$") symbolOfTerm(name.init) else symbolOfIdent(name)
+      def pathOf(s: String) = s"${s.replace('.', '/')}.class"
+      sym.toOption map (s => pathOf(flatPath(s)))
+    } else {
+      None
+    }
+  }
   def translateEnclosingClass(n: String) = symbolOfTerm(n).enclClass.toOption map flatPath
 
+  /** If unable to find a resource foo.class, try taking foo as a symbol in scope
+   *  and use its java class name as a resource to load.
+   *
+   *  $intp.classLoader classBytes "Bippy" or $intp.classLoader getResource "Bippy.class" just work.
+   */
   private class TranslatingClassLoader(parent: ClassLoader) extends util.AbstractFileClassLoader(replOutput.dir, parent) {
-    /** Overridden here to try translating a simple name to the generated
-     *  class name if the original attempt fails.  This method is used by
-     *  getResourceAsStream as well as findClass.
-     */
-    override protected def findAbstractFile(name: String): AbstractFile =
-      super.findAbstractFile(name) match {
-        case null if _initializeComplete => translatePath(name) map (super.findAbstractFile(_)) orNull
-        case file => file
-      }
+    override protected def findAbstractFile(name: String): AbstractFile = super.findAbstractFile(name) match {
+      case null if _initializeComplete => translateSimpleResource(name) map super.findAbstractFile orNull
+      case file => file
+    }
   }
   private def makeClassLoader(): util.AbstractFileClassLoader =
     new TranslatingClassLoader(parentClassLoader match {

test/files/run/t8843-repl-xlat.scala

@@ -0,0 +1,33 @@
+
+import scala.tools.partest.SessionTest
+
+// Handy hamburger helper for repl resources
+object Test extends SessionTest {
+  def session =
+"""Type in expressions to have them evaluated.
+Type :help for more information.
+
+scala> $intp.isettings.unwrapStrings = false
+$intp.isettings.unwrapStrings: Boolean = false
+
+scala> class Bippy
+defined class Bippy
+
+scala> $intp.classLoader getResource "Bippy.class"
+res0: java.net.URL = memory:(memory)/$line4/$read$$iw$$iw$Bippy.class
+
+scala> ($intp.classLoader getResources "Bippy.class").nextElement
+res1: java.net.URL = memory:(memory)/$line4/$read$$iw$$iw$Bippy.class
+
+scala> ($intp.classLoader classBytes "Bippy").nonEmpty
+res2: Boolean = true
+
+scala> ($intp.classLoader classAsStream "Bippy") != null
+res3: Boolean = true
+
+scala> $intp.classLoader getResource "Bippy"
+res4: java.net.URL = null
+
+scala> :quit"""
+}
+

test/junit/scala/reflect/internal/PrintersTest.scala

@@ -24,10 +24,10 @@ object PrinterHelper {
     resultCode.lines mkString s"$LF"
 
   def assertResultCode(code: String)(parsedCode: String = "", typedCode: String = "", wrap: Boolean = false, printRoot: Boolean = false) = {
-    def toolboxTree(tree: => Tree) = try{
+    def toolboxTree(tree: => Tree) = try {
         tree
       } catch {
-        case e:scala.tools.reflect.ToolBoxError => throw new Exception(e.getMessage + ": " + code)
+        case e:scala.tools.reflect.ToolBoxError => throw new Exception(e.getMessage + ": " + code, e)
       }
 
     def wrapCode(source: String) = {
@@ -1186,4 +1186,4 @@ trait QuasiTreesPrintTests {
     |  };
     |  ()
     |}""")
-}
+}

test/junit/scala/reflect/internal/util/AbstractFileClassLoaderTest.scala

@@ -0,0 +1,138 @@
+package scala.reflect.internal.util
+
+import org.junit.Assert._
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(classOf[JUnit4])
+class AbstractFileClassLoaderTest {
+
+  import scala.reflect.io._
+  import scala.io.Source
+  import scala.io.Codec.UTF8
+  import scala.reflect.io.Streamable
+  import java.net.{ URLClassLoader, URL }
+
+  implicit def `we love utf8` = UTF8
+  implicit class `abs file ops`(f: AbstractFile) {
+    def writeContent(s: String): Unit = Streamable.closing(f.bufferedOutput)(os => os write s.getBytes(UTF8.charSet))
+  }
+  implicit class `url slurp`(url: URL) {
+    def slurp(): String = Streamable.slurp(url)
+  }
+
+  val NoClassLoader: ClassLoader = null
+
+  def fuzzBuzzBooz: (AbstractFile, AbstractFile) = {
+    val fuzz = new VirtualDirectory("fuzz", None)
+    val buzz = fuzz subdirectoryNamed "buzz"
+    val booz = buzz fileNamed "booz.class"
+    (fuzz, booz)
+  }
+
+  @Test
+  def afclGetsParent(): Unit = {
+    val p = new URLClassLoader(Array.empty[URL])
+    val d = new VirtualDirectory("vd", None)
+    val x = new AbstractFileClassLoader(d, p)
+    assertSame(p, x.getParent)
+  }
+
+  @Test
+  def afclGetsResource(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    val x = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val r = x.getResource("buzz/booz.class")
+    assertNotNull(r)
+    assertEquals("hello, world", r.slurp())
+  }
+
+  @Test
+  def afclGetsResourceFromParent(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    val (fuzz_, booz_) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    booz_ writeContent "hello, world_"
+    val p = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val x = new AbstractFileClassLoader(fuzz_, p)
+    val r = x.getResource("buzz/booz.class")
+    assertNotNull(r)
+    assertEquals("hello, world", r.slurp())
+  }
+
+  @Test
+  def afclGetsResourceInDefaultPackage(): Unit = {
+    val fuzz = new VirtualDirectory("fuzz", None)
+    val booz = fuzz fileNamed "booz.class"
+    val bass = fuzz fileNamed "bass"
+    booz writeContent "hello, world"
+    bass writeContent "lo tone"
+    val x = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val r = x.getResource("booz.class")
+    assertNotNull(r)
+    assertEquals("hello, world", r.slurp())
+    assertEquals("lo tone", (x getResource "bass").slurp())
+  }
+
+  // SI-8843
+  @Test
+  def afclGetsResources(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    val x = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val e = x.getResources("buzz/booz.class")
+    assertTrue(e.hasMoreElements)
+    assertEquals("hello, world", e.nextElement.slurp())
+    assertFalse(e.hasMoreElements)
+  }
+
+  @Test
+  def afclGetsResourcesFromParent(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    val (fuzz_, booz_) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    booz_ writeContent "hello, world_"
+    val p = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val x = new AbstractFileClassLoader(fuzz_, p)
+    val e = x.getResources("buzz/booz.class")
+    assertTrue(e.hasMoreElements)
+    assertEquals("hello, world", e.nextElement.slurp())
+    assertTrue(e.hasMoreElements)
+    assertEquals("hello, world_", e.nextElement.slurp())
+    assertFalse(e.hasMoreElements)
+  }
+
+  @Test
+  def afclGetsResourceAsStream(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    val x = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val r = x.getResourceAsStream("buzz/booz.class")
+    assertNotNull(r)
+    assertEquals("hello, world", Streamable.closing(r)(is => Source.fromInputStream(is).mkString))
+  }
+
+  @Test
+  def afclGetsClassBytes(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    val x = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val b = x.classBytes("buzz/booz.class")
+    assertEquals("hello, world", new String(b, UTF8.charSet))
+  }
+
+  @Test
+  def afclGetsClassBytesFromParent(): Unit = {
+    val (fuzz, booz) = fuzzBuzzBooz
+    val (fuzz_, booz_) = fuzzBuzzBooz
+    booz writeContent "hello, world"
+    booz_ writeContent "hello, world_"
+
+    val p = new AbstractFileClassLoader(fuzz, NoClassLoader)
+    val x = new AbstractFileClassLoader(fuzz_, p)
+    val b = x.classBytes("buzz/booz.class")
+    assertEquals("hello, world", new String(b, UTF8.charSet))
+  }
+}