Enable flat classpath by default

Implements VirtualDirectoryFlatClassPath, which is required for the
presentation compiler created for the repl's tab-completion.

Various minor cleanups in the flat classpath implementation.

8 files changed, 137 insertions, 110 deletions

diff --git a/src/compiler/scala/tools/nsc/classpath/AggregateFlatClassPath.scala b/src/compiler/scala/tools/nsc/classpath/AggregateFlatClassPath.scala
index 3f06264e3c..7bfb3240eb 100644
--- a/src/compiler/scala/tools/nsc/classpath/AggregateFlatClassPath.scala
+++ b/src/compiler/scala/tools/nsc/classpath/AggregateFlatClassPath.scala
@@ -18,7 +18,6 @@ import scala.tools.nsc.util.ClassRepresentation
  * @param aggregates classpath instances containing entries which this class processes
  */
 case class AggregateFlatClassPath(aggregates: Seq[FlatClassPath]) extends FlatClassPath {
-
   override def findClassFile(className: String): Option[AbstractFile] = {
     @tailrec
     def find(aggregates: Seq[FlatClassPath]): Option[AbstractFile] =
@@ -37,8 +36,7 @@ case class AggregateFlatClassPath(aggregates: Seq[FlatClassPath]) extends FlatCl
     @tailrec
     def findEntry[T <: ClassRepClassPathEntry](aggregates: Seq[FlatClassPath], getEntries: FlatClassPath => Seq[T]): Option[T] =
       if (aggregates.nonEmpty) {
-        val entry = getEntries(aggregates.head)
-          .find(_.name == simpleClassName)
+        val entry = getEntries(aggregates.head).find(_.name == simpleClassName)
         if (entry.isDefined) entry
         else findEntry(aggregates.tail, getEntries)
       } else None
@@ -46,7 +44,11 @@ case class AggregateFlatClassPath(aggregates: Seq[FlatClassPath]) extends FlatCl
     val classEntry = findEntry(aggregates, classesGetter(pkg))
     val sourceEntry = findEntry(aggregates, sourcesGetter(pkg))
 
-    mergeClassesAndSources(classEntry.toList, sourceEntry.toList).headOption
+    (classEntry, sourceEntry) match {
+      case (Some(c), Some(s)) => Some(ClassAndSourceFilesEntry(c.file, s.file))
+      case (c @ Some(_), _) => c
+      case (_, s) => s
+    }
   }
 
   override def asURLs: Seq[URL] = aggregates.flatMap(_.asURLs)
diff --git a/src/compiler/scala/tools/nsc/classpath/DirectoryFlatClassPath.scala b/src/compiler/scala/tools/nsc/classpath/DirectoryFlatClassPath.scala
index 81d2f7320f..e3964dfa78 100644
--- a/src/compiler/scala/tools/nsc/classpath/DirectoryFlatClassPath.scala
+++ b/src/compiler/scala/tools/nsc/classpath/DirectoryFlatClassPath.scala
@@ -4,7 +4,6 @@
 package scala.tools.nsc.classpath
 
 import java.io.File
-import java.io.FileFilter
 import java.net.URL
 import scala.reflect.io.AbstractFile
 import scala.reflect.io.PlainFile
@@ -12,97 +11,101 @@ import scala.tools.nsc.util.ClassRepresentation
 import FileUtils._
 
 /**
- * A trait allowing to look for classpath entries of given type in directories.
- * It provides common logic for classes handling class and source files.
+ * A trait allowing to look for classpath entries in directories. It provides common logic for
+ * classes handling class and source files.
  * It makes use of the fact that in the case of nested directories it's easy to find a file
  * when we have a name of a package.
+ * It abstracts over the file representation to work with both JFile and AbstractFile.
  */
-trait DirectoryFileLookup[FileEntryType <: ClassRepClassPathEntry] extends FlatClassPath {
-  val dir: File
-  assert(dir != null, "Directory file in DirectoryFileLookup cannot be null")
+trait DirectoryLookup[FileEntryType <: ClassRepClassPathEntry] extends FlatClassPath {
+  type F
+
+  val dir: F
+
+  protected def emptyFiles: Array[F] // avoids reifying ClassTag[F]
+  protected def getSubDir(dirName: String): Option[F]
+  protected def listChildren(dir: F, filter: Option[F => Boolean] = None): Array[F]
+  protected def getName(f: F): String
+  protected def toAbstractFile(f: F): AbstractFile
+  protected def isPackage(f: F): Boolean
 
-  override def asURLs: Seq[URL] = Seq(dir.toURI.toURL)
-  override def asClassPathStrings: Seq[String] = Seq(dir.getPath)
+  protected def createFileEntry(file: AbstractFile): FileEntryType
+  protected def isMatchingFile(f: F): Boolean
 
-  import FlatClassPath.RootPackage
-  private def getDirectory(forPackage: String): Option[File] = {
-    if (forPackage == RootPackage) {
+  private def getDirectory(forPackage: String): Option[F] = {
+    if (forPackage == FlatClassPath.RootPackage) {
       Some(dir)
     } else {
       val packageDirName = FileUtils.dirPath(forPackage)
-      val packageDir = new File(dir, packageDirName)
-      if (packageDir.exists && packageDir.isDirectory) {
-        Some(packageDir)
-      } else None
+      getSubDir(packageDirName)
     }
   }
 
-  override private[nsc] def packages(inPackage: String): Seq[PackageEntry] = {
+  private[nsc] def packages(inPackage: String): Seq[PackageEntry] = {
     val dirForPackage = getDirectory(inPackage)
-    val nestedDirs: Array[File] = dirForPackage match {
-      case None => Array.empty
-      case Some(directory) => directory.listFiles(DirectoryFileLookup.packageDirectoryFileFilter)
+    val nestedDirs: Array[F] = dirForPackage match {
+      case None => emptyFiles
+      case Some(directory) => listChildren(directory, Some(isPackage))
     }
     val prefix = PackageNameUtils.packagePrefix(inPackage)
-    val entries = nestedDirs map { file =>
-      PackageEntryImpl(prefix + file.getName)
-    }
-    entries
+    nestedDirs.map(f => PackageEntryImpl(prefix + getName(f)))
   }
 
   protected def files(inPackage: String): Seq[FileEntryType] = {
     val dirForPackage = getDirectory(inPackage)
-    val files: Array[File] = dirForPackage match {
-      case None => Array.empty
-      case Some(directory) => directory.listFiles(fileFilter)
-    }
-    val entries = files map { file =>
-      val wrappedFile = new scala.reflect.io.File(file)
-      createFileEntry(new PlainFile(wrappedFile))
+    val files: Array[F] = dirForPackage match {
+      case None => emptyFiles
+      case Some(directory) => listChildren(directory, Some(isMatchingFile))
     }
-    entries
+    files.map(f => createFileEntry(toAbstractFile(f)))
   }
 
-  override private[nsc] def list(inPackage: String): FlatClassPathEntries = {
+  private[nsc] def list(inPackage: String): FlatClassPathEntries = {
     val dirForPackage = getDirectory(inPackage)
-    val files: Array[File] = dirForPackage match {
-      case None => Array.empty
-      case Some(directory) => directory.listFiles()
+    val files: Array[F] = dirForPackage match {
+      case None => emptyFiles
+      case Some(directory) => listChildren(directory)
     }
     val packagePrefix = PackageNameUtils.packagePrefix(inPackage)
     val packageBuf = collection.mutable.ArrayBuffer.empty[PackageEntry]
     val fileBuf = collection.mutable.ArrayBuffer.empty[FileEntryType]
     for (file <- files) {
-      if (file.isPackage) {
-        val pkgEntry = PackageEntryImpl(packagePrefix + file.getName)
-        packageBuf += pkgEntry
-      } else if (fileFilter.accept(file)) {
-        val wrappedFile = new scala.reflect.io.File(file)
-        val abstractFile = new PlainFile(wrappedFile)
-        fileBuf += createFileEntry(abstractFile)
-      }
+      if (isPackage(file))
+        packageBuf += PackageEntryImpl(packagePrefix + getName(file))
+      else if (isMatchingFile(file))
+        fileBuf += createFileEntry(toAbstractFile(file))
     }
     FlatClassPathEntries(packageBuf, fileBuf)
   }
-
-  protected def createFileEntry(file: AbstractFile): FileEntryType
-  protected def fileFilter: FileFilter
 }
 
-object DirectoryFileLookup {
+trait JFileDirectoryLookup[FileEntryType <: ClassRepClassPathEntry] extends DirectoryLookup[FileEntryType] {
+  type F = File
 
-  private[classpath] object packageDirectoryFileFilter extends FileFilter {
-    override def accept(pathname: File): Boolean = pathname.isPackage
+  protected def emptyFiles: Array[File] = Array.empty
+  protected def getSubDir(packageDirName: String): Option[File] = {
+    val packageDir = new File(dir, packageDirName)
+    if (packageDir.exists && packageDir.isDirectory) Some(packageDir)
+    else None
   }
-}
+  protected def listChildren(dir: File, filter: Option[File => Boolean]): Array[File] = filter match {
+    case Some(f) => dir.listFiles(mkFileFilter(f))
+    case None => dir.listFiles()
+  }
+  protected def getName(f: File): String = f.getName
+  protected def toAbstractFile(f: File): AbstractFile = new PlainFile(new scala.reflect.io.File(f))
+  protected def isPackage(f: File): Boolean = f.isPackage
 
-case class DirectoryFlatClassPath(dir: File)
-  extends DirectoryFileLookup[ClassFileEntryImpl]
-  with NoSourcePaths {
+  assert(dir != null, "Directory file in DirectoryFileLookup cannot be null")
 
+  def asURLs: Seq[URL] = Seq(dir.toURI.toURL)
+  def asClassPathStrings: Seq[String] = Seq(dir.getPath)
+}
+
+case class DirectoryFlatClassPath(dir: File) extends JFileDirectoryLookup[ClassFileEntryImpl] with NoSourcePaths {
   override def findClass(className: String): Option[ClassRepresentation[AbstractFile]] = findClassFile(className) map ClassFileEntryImpl
 
-  override def findClassFile(className: String): Option[AbstractFile] = {
+  def findClassFile(className: String): Option[AbstractFile] = {
     val relativePath = FileUtils.dirPath(className)
     val classFile = new File(s"$dir/$relativePath.class")
     if (classFile.exists) {
@@ -112,31 +115,19 @@ case class DirectoryFlatClassPath(dir: File)
     } else None
   }
 
-  override protected def createFileEntry(file: AbstractFile): ClassFileEntryImpl = ClassFileEntryImpl(file)
-  override protected def fileFilter: FileFilter = DirectoryFlatClassPath.classFileFilter
-
-  override private[nsc] def classes(inPackage: String): Seq[ClassFileEntry] = files(inPackage)
-}
-
-object DirectoryFlatClassPath {
+  protected def createFileEntry(file: AbstractFile): ClassFileEntryImpl = ClassFileEntryImpl(file)
+  protected def isMatchingFile(f: File): Boolean = f.isClass
 
-  private val classFileFilter = new FileFilter {
-    override def accept(pathname: File): Boolean = pathname.isClass
-  }
+  private[nsc] def classes(inPackage: String): Seq[ClassFileEntry] = files(inPackage)
 }
 
-case class DirectoryFlatSourcePath(dir: File)
-  extends DirectoryFileLookup[SourceFileEntryImpl]
-  with NoClassPaths {
+case class DirectoryFlatSourcePath(dir: File) extends JFileDirectoryLookup[SourceFileEntryImpl] with NoClassPaths {
+  def asSourcePathString: String = asClassPathString
 
-  override def asSourcePathString: String = asClassPathString
+  protected def createFileEntry(file: AbstractFile): SourceFileEntryImpl = SourceFileEntryImpl(file)
+  protected def isMatchingFile(f: File): Boolean = endsScalaOrJava(f.getName)
 
-  override protected def createFileEntry(file: AbstractFile): SourceFileEntryImpl = SourceFileEntryImpl(file)
-  override protected def fileFilter: FileFilter = DirectoryFlatSourcePath.sourceFileFilter
-
-  override def findClass(className: String): Option[ClassRepresentation[AbstractFile]] = {
-    findSourceFile(className) map SourceFileEntryImpl
-  }
+  override def findClass(className: String): Option[ClassRepresentation[AbstractFile]] = findSourceFile(className) map SourceFileEntryImpl
 
   private def findSourceFile(className: String): Option[AbstractFile] = {
     val relativePath = FileUtils.dirPath(className)
@@ -151,12 +142,5 @@ case class DirectoryFlatSourcePath(dir: File)
     }
   }
 
-  override private[nsc] def sources(inPackage: String): Seq[SourceFileEntry] = files(inPackage)
-}
-
-object DirectoryFlatSourcePath {
-
-  private val sourceFileFilter = new FileFilter {
-    override def accept(pathname: File): Boolean = endsScalaOrJava(pathname.getName)
-  }
+  private[nsc] def sources(inPackage: String): Seq[SourceFileEntry] = files(inPackage)
 }
diff --git a/src/compiler/scala/tools/nsc/classpath/FileUtils.scala b/src/compiler/scala/tools/nsc/classpath/FileUtils.scala
index ee2528e15c..bbcfcb24ca 100644
--- a/src/compiler/scala/tools/nsc/classpath/FileUtils.scala
+++ b/src/compiler/scala/tools/nsc/classpath/FileUtils.scala
@@ -3,7 +3,7 @@
  */
 package scala.tools.nsc.classpath
 
-import java.io.{ File => JFile }
+import java.io.{File => JFile, FileFilter}
 import java.net.URL
 import scala.reflect.internal.FatalError
 import scala.reflect.io.AbstractFile
@@ -65,4 +65,8 @@ object FileUtils {
   // because then some tests in partest don't pass
   private def mayBeValidPackage(dirName: String): Boolean =
     (dirName != "META-INF") && (dirName != "") && (dirName.charAt(0) != '.')
+
+  def mkFileFilter(f: JFile => Boolean) = new FileFilter {
+    def accept(pathname: JFile): Boolean = f(pathname)
+  }
 }
diff --git a/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala b/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
index cb201617d2..e95ffe02e3 100644
--- a/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
+++ b/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
@@ -28,11 +28,8 @@ trait FlatClassPath extends ClassFileLookup[AbstractFile] {
   override def findClass(className: String): Option[ClassRepresentation[AbstractFile]] = {
     val (pkg, simpleClassName) = PackageNameUtils.separatePkgAndClassNames(className)
 
-    val foundClassFromClassFiles = classes(pkg)
-      .find(_.name == simpleClassName)
-
-    def findClassInSources = sources(pkg)
-      .find(_.name == simpleClassName)
+    val foundClassFromClassFiles = classes(pkg).find(_.name == simpleClassName)
+    def findClassInSources = sources(pkg).find(_.name == simpleClassName)
 
     foundClassFromClassFiles orElse findClassInSources
   }
@@ -50,7 +47,7 @@ case class FlatClassPathEntries(packages: Seq[PackageEntry], classesAndSources:
 object FlatClassPathEntries {
   import scala.language.implicitConversions
   // to have working unzip method
-  implicit def entry2Tuple(entry: FlatClassPathEntries) = (entry.packages, entry.classesAndSources)
+  implicit def entry2Tuple(entry: FlatClassPathEntries): (Seq[PackageEntry], Seq[ClassRepClassPathEntry]) = (entry.packages, entry.classesAndSources)
 }
 
 sealed trait ClassRepClassPathEntry extends ClassRepresentation[AbstractFile]
diff --git a/src/compiler/scala/tools/nsc/classpath/FlatClassPathFactory.scala b/src/compiler/scala/tools/nsc/classpath/FlatClassPathFactory.scala
index d8ca325885..463301696e 100644
--- a/src/compiler/scala/tools/nsc/classpath/FlatClassPathFactory.scala
+++ b/src/compiler/scala/tools/nsc/classpath/FlatClassPathFactory.scala
@@ -3,6 +3,7 @@
  */
 package scala.tools.nsc.classpath
 
+import scala.reflect.io.VirtualDirectory
 import scala.tools.nsc.Settings
 import scala.tools.nsc.io.AbstractFile
 import FileUtils.AbstractFileOps
@@ -12,16 +13,9 @@ import FileUtils.AbstractFileOps
  * it uses proper type of classpath depending on a types of particular files containing sources or classes.
  */
 class FlatClassPathFactory(settings: Settings) extends ClassPathFactory[FlatClassPath] {
+  def newClassPath(file: AbstractFile): FlatClassPath = FlatClassPathFactory.newClassPath(file, settings)
 
-  override def newClassPath(file: AbstractFile): FlatClassPath =
-    if (file.isJarOrZip)
-      ZipAndJarFlatClassPathFactory.create(file, settings)
-    else if (file.isDirectory)
-      new DirectoryFlatClassPath(file.file)
-    else
-      sys.error(s"Unsupported classpath element: $file")
-
-  override def sourcesInPath(path: String): List[FlatClassPath] =
+  def sourcesInPath(path: String): List[FlatClassPath] =
     for {
       file <- expandPath(path, expandStar = false)
       dir <- Option(AbstractFile getDirectory file)
@@ -35,3 +29,16 @@ class FlatClassPathFactory(settings: Settings) extends ClassPathFactory[FlatClas
     else
       sys.error(s"Unsupported sourcepath element: $file")
 }
+
+object FlatClassPathFactory {
+  def newClassPath(file: AbstractFile, settings: Settings): FlatClassPath = file match {
+    case vd: VirtualDirectory => VirtualDirectoryFlatClassPath(vd)
+    case _ =>
+      if (file.isJarOrZip)
+        ZipAndJarFlatClassPathFactory.create(file, settings)
+      else if (file.isDirectory)
+        new DirectoryFlatClassPath(file.file)
+      else
+        sys.error(s"Unsupported classpath element: $file")
+  }
+}
diff --git a/src/compiler/scala/tools/nsc/classpath/VirtualDirectoryFlatClassPath.scala b/src/compiler/scala/tools/nsc/classpath/VirtualDirectoryFlatClassPath.scala
new file mode 100644
index 0000000000..06cdab583c
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/classpath/VirtualDirectoryFlatClassPath.scala
@@ -0,0 +1,39 @@
+package scala.tools.nsc.classpath
+
+import scala.tools.nsc.util.ClassRepresentation
+import scala.reflect.io.{Path, PlainFile, VirtualDirectory, AbstractFile}
+import FileUtils._
+import java.net.URL
+
+case class VirtualDirectoryFlatClassPath(dir: VirtualDirectory) extends FlatClassPath with DirectoryLookup[ClassFileEntryImpl] with NoSourcePaths {
+  type F = AbstractFile
+
+  protected def emptyFiles: Array[AbstractFile] = Array.empty
+  protected def getSubDir(packageDirName: String): Option[AbstractFile] =
+    Option(dir.lookupName(packageDirName, directory = true))
+  protected def listChildren(dir: AbstractFile, filter: Option[AbstractFile => Boolean] = None): Array[F] = filter match {
+    case Some(f) => dir.iterator.filter(f).toArray
+    case _ => dir.toArray
+  }
+  def getName(f: AbstractFile): String = f.name
+  def toAbstractFile(f: AbstractFile): AbstractFile = f
+  def isPackage(f: AbstractFile): Boolean = f.isPackage
+
+  // mimic the behavior of the old nsc.util.DirectoryClassPath
+  def asURLs: Seq[URL] = Seq(new URL(dir.name))
+  def asClassPathStrings: Seq[String] = Seq(dir.path)
+
+  override def findClass(className: String): Option[ClassRepresentation[AbstractFile]] = findClassFile(className) map ClassFileEntryImpl
+
+  def findClassFile(className: String): Option[AbstractFile] = {
+    val relativePath = FileUtils.dirPath(className)
+    val classFile = new PlainFile(Path(s"$dir/$relativePath.class"))
+    if (classFile.exists) Some(classFile)
+    else None
+  }
+
+  private[nsc] def classes(inPackage: String): Seq[ClassFileEntry] = files(inPackage)
+
+  protected def createFileEntry(file: AbstractFile): ClassFileEntryImpl = ClassFileEntryImpl(file)
+  protected def isMatchingFile(f: AbstractFile): Boolean = f.isClass
+}
diff --git a/src/compiler/scala/tools/nsc/classpath/ZipAndJarFileLookupFactory.scala b/src/compiler/scala/tools/nsc/classpath/ZipAndJarFileLookupFactory.scala
index 85c7c3c843..6ec3805d8b 100644
--- a/src/compiler/scala/tools/nsc/classpath/ZipAndJarFileLookupFactory.scala
+++ b/src/compiler/scala/tools/nsc/classpath/ZipAndJarFileLookupFactory.scala
@@ -19,7 +19,6 @@ import FileUtils._
  * when there are a lot of projects having a lot of common dependencies.
  */
 sealed trait ZipAndJarFileLookupFactory {
-
   private val cache = collection.mutable.Map.empty[AbstractFile, FlatClassPath]
 
   def create(zipFile: AbstractFile, settings: Settings): FlatClassPath = {
@@ -44,7 +43,6 @@ sealed trait ZipAndJarFileLookupFactory {
  * It should be the only way of creating them as it provides caching.
  */
 object ZipAndJarFlatClassPathFactory extends ZipAndJarFileLookupFactory {
-
   private case class ZipArchiveFlatClassPath(zipFile: File)
     extends ZipArchiveFileLookup[ClassFileEntryImpl]
     with NoSourcePaths {
@@ -67,10 +65,7 @@ object ZipAndJarFlatClassPathFactory extends ZipAndJarFileLookupFactory {
    * with a particularly prepared scala-library.jar. It should have all classes listed in the manifest like e.g. this entry:
    * Name: scala/Function2$mcFJD$sp.class
    */
-  private case class ManifestResourcesFlatClassPath(file: ManifestResources)
-    extends FlatClassPath
-    with NoSourcePaths {
-
+  private case class ManifestResourcesFlatClassPath(file: ManifestResources) extends FlatClassPath with NoSourcePaths {
     override def findClassFile(className: String): Option[AbstractFile] = {
       val (pkg, simpleClassName) = PackageNameUtils.separatePkgAndClassNames(className)
       classes(pkg).find(_.name == simpleClassName).map(_.file)
@@ -163,7 +158,6 @@ object ZipAndJarFlatClassPathFactory extends ZipAndJarFileLookupFactory {
  * It should be the only way of creating them as it provides caching.
  */
 object ZipAndJarFlatSourcePathFactory extends ZipAndJarFileLookupFactory {
-
   private case class ZipArchiveFlatSourcePath(zipFile: File)
     extends ZipArchiveFileLookup[SourceFileEntryImpl]
     with NoClassPaths {
diff --git a/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala b/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala
index 1d0de57779..a24d989306 100644
--- a/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala
+++ b/src/compiler/scala/tools/nsc/classpath/ZipArchiveFileLookup.scala
@@ -57,7 +57,7 @@ trait ZipArchiveFileLookup[FileEntryType <: ClassRepClassPathEntry] extends Flat
     } getOrElse FlatClassPathEntries(Seq.empty, Seq.empty)
   }
 
-  private def findDirEntry(pkg: String) = {
+  private def findDirEntry(pkg: String): Option[archive.DirEntry] = {
     val dirName = s"${FileUtils.dirPath(pkg)}/"
     archive.allDirs.get(dirName)
   }