Merge pull request scala#4627 from som-snytt/issue/9396

SI-9396 Runner computes path only once

Author: lrytz

src/compiler/scala/tools/nsc/GenericRunnerSettings.scala

@@ -9,7 +9,7 @@ import java.net.URL
 import scala.tools.util.PathResolverFactory
 
 class GenericRunnerSettings(error: String => Unit) extends Settings(error) {
-  def classpathURLs: Seq[URL] = PathResolverFactory.create(this).resultAsURLs
+  lazy val classpathURLs: Seq[URL] = PathResolverFactory.create(this).resultAsURLs
 
   val howtorun =
     ChoiceSetting(

src/compiler/scala/tools/nsc/settings/ScalaSettings.scala

@@ -22,13 +22,9 @@ trait ScalaSettings extends AbsScalaSettings
   /** Set of settings */
   protected[scala] lazy val allSettings = mutable.HashSet[Setting]()
 
-  /** Against my better judgment, giving in to martin here and allowing
-   *  CLASSPATH to be used automatically.  So for the user-specified part
-   *  of the classpath:
-   *
-   *  - If -classpath or -cp is given, it is that
-   *  - Otherwise, if CLASSPATH is set, it is that
-   *  - If neither of those, then "." is used.
+  /** The user class path, specified by `-classpath` or `-cp`,
+   *  defaults to the value of CLASSPATH env var if it is set, as in Java,
+   *  or else to `"."` for the current user directory.
    */
   protected def defaultClasspath = sys.env.getOrElse("CLASSPATH", ".")
 

src/compiler/scala/tools/util/PathResolver.scala

@@ -254,17 +254,7 @@ abstract class PathResolverBase[BaseClassPathType <: ClassFileLookup[AbstractFil
      * TODO: we should refactor this as a separate -bootstrap option to have a clean implementation, no? */
     def sourcePath          = if (!settings.isScaladoc) cmdLineOrElse("sourcepath", Defaults.scalaSourcePath) else ""
 
-    /** Against my better judgment, giving in to martin here and allowing
-     *  CLASSPATH to be used automatically.  So for the user-specified part
-     *  of the classpath:
-     *
-     *  - If -classpath or -cp is given, it is that
-     *  - Otherwise, if CLASSPATH is set, it is that
-     *  - If neither of those, then "." is used.
-     */
-    def userClassPath =
-      if (!settings.classpath.isDefault) settings.classpath.value
-      else sys.env.getOrElse("CLASSPATH", ".")
+    def userClassPath = settings.classpath.value  // default is specified by settings and can be overridden there
 
     import classPathFactory._