From 50d350abd05af7c9ea92dd2451fef5272c715c46 Mon Sep 17 00:00:00 2001
From: Mark Harrah <dmharrah@gmail.com>
Date: Sun, 23 Aug 2009 22:21:15 -0400
Subject: [PATCH] Compilation with analysis independent of Scala version of
 sbt. Basic test for this.

---
 compile/Compiler.scala                        | 78 +++++++++--------
 compile/ComponentCompiler.scala               | 25 +++---
 .../src/test/scala/TestCompile.scala          | 20 -----
 compile/src/test/scala/CompileTest.scala      | 50 +++++++++++
 launch/Boot.scala                             |  4 +-
 launch/BootConfiguration.scala                |  9 +-
 launch/FilteredLoader.scala                   |  4 +-
 launch/Launch.scala                           | 54 ++++++++----
 .../src/main/java/xsbti/{boot => }/Exit.java  |  2 +-
 .../src/main/java/xsbti/Launcher.java         | 21 +++++
 .../java/xsbti/{boot => }/MainResult.java     |  2 +-
 .../main/java/xsbti/{boot => }/Reboot.java    |  2 +-
 .../xsbti/{boot => }/SbtConfiguration.java    |  2 +-
 .../main/java/xsbti/{boot => }/SbtMain.java   |  2 +-
 .../src/main/java/xsbti/SbtProvider.java      | 12 +++
 .../java/xsbti/{boot => }/ScalaProvider.java  |  2 +-
 .../src/main/java/xsbti/boot/Launcher.java    | 19 -----
 launch/src/test/scala/ScalaProviderTest.scala | 84 +++++++++++++++----
 notes                                         |  5 +-
 project/build/XSbt.scala                      | 55 ++++++++----
 util/classpath/DualLoader.scala               | 80 ++++++++++++++++++
 util/io/FileUtilities.scala                   | 16 +++-
 util/io/PathMapper.scala                      |  2 +
 util/io/src/test/scala/WithFiles.scala        | 25 ++++++
 24 files changed, 426 insertions(+), 149 deletions(-)
 create mode 100644 compile/src/test/scala/CompileTest.scala
 rename launch/interface/src/main/java/xsbti/{boot => }/Exit.java (75%)
 create mode 100644 launch/interface/src/main/java/xsbti/Launcher.java
 rename launch/interface/src/main/java/xsbti/{boot => }/MainResult.java (62%)
 rename launch/interface/src/main/java/xsbti/{boot => }/Reboot.java (78%)
 rename launch/interface/src/main/java/xsbti/{boot => }/SbtConfiguration.java (88%)
 rename launch/interface/src/main/java/xsbti/{boot => }/SbtMain.java (80%)
 create mode 100644 launch/interface/src/main/java/xsbti/SbtProvider.java
 rename launch/interface/src/main/java/xsbti/{boot => }/ScalaProvider.java (88%)
 delete mode 100644 launch/interface/src/main/java/xsbti/boot/Launcher.java
 create mode 100644 util/classpath/DualLoader.scala
 create mode 100644 util/io/src/test/scala/WithFiles.scala

diff --git a/compile/Compiler.scala b/compile/Compiler.scala
index 1d00f7206..449ceee46 100644
--- a/compile/Compiler.scala
+++ b/compile/Compiler.scala
@@ -9,42 +9,50 @@ import java.net.URLClassLoader
 * these call Scala code for a different Scala version, they must be compiled for the version of Scala being used.
 * It is essential that the provided 'scalaVersion' be a 1:1 mapping to the actual version of Scala being used for compilation
 * (-SNAPSHOT is not acceptable).  Otherwise, binary compatibility issues will ensue!*/
-class Compiler(scalaLoader: ClassLoader, val scalaVersion: String, private[xsbt] val manager: ComponentManager)
-{
-	// this is the instance used to compile the analysis
-	lazy val componentCompiler = new ComponentCompiler(this)
-	/** A basic interface to the compiler.  It is called in the same virtual machine, but no dependency analysis is done.  This
-	* is used, for example, to compile the interface/plugin code.*/
-	object raw
-	{
-		def apply(arguments: Seq[String])
-		{
-			// reflection is required for binary compatibility
-			 // The following import ensures there is a compile error if the class name changes,
-			 //   but it should not be otherwise directly referenced
-			import scala.tools.nsc.Main
 
-			val mainClass = Class.forName("scala.tools.nsc.Main", true, scalaLoader)
-			val main = mainClass.asInstanceOf[{def process(args: Array[String]): Unit }]
-			main.process(arguments.toArray)
-		}
-	}
-	/** Interface to the compiler that uses the dependency analysis plugin.*/
-	object analysis
+/** A basic interface to the compiler.  It is called in the same virtual machine, but no dependency analysis is done.  This
+* is used, for example, to compile the interface/plugin code.*/
+class RawCompiler(scalaLoader: ClassLoader)
+{
+	def apply(arguments: Seq[String])
 	{
-		/** The jar containing the compiled plugin and the compiler interface code.  This will be passed to scalac as a compiler plugin
-		* and used to load the class that actually interfaces with Global.*/
-		private lazy val interfaceJar = componentCompiler(ComponentCompiler.compilerInterfaceID)
-		def apply(arguments: Seq[String], callback: AnalysisCallback, maximumErrors: Int, log: Logger)
-		{
-			val argsWithPlugin = ("-Xplugin:" + interfaceJar.getAbsolutePath) :: arguments.toList
-			val interfaceLoader = new URLClassLoader(Array(interfaceJar.toURI.toURL), scalaLoader)
-			val interface = Class.forName("xsbt.CompilerInterface", true, interfaceLoader).newInstance
-			val runnable = interface.asInstanceOf[{ def run(args: Array[String], callback: AnalysisCallback, maximumErrors: Int, log: Logger): Unit }]
-			 // these arguments are safe to pass across the ClassLoader boundary because the types are defined in Java
-			//  so they will be binary compatible across all versions of Scala
-			runnable.run(argsWithPlugin.toArray, callback, maximumErrors, log)
-		}
-		def forceInitialization() {interfaceJar }
+		// reflection is required for binary compatibility
+			// The following import ensures there is a compile error if the class name changes,
+			//   but it should not be otherwise directly referenced
+		import scala.tools.nsc.Main
+
+		val mainClass = Class.forName("scala.tools.nsc.Main", true, scalaLoader)
+		val process = mainClass.getMethod("process", classOf[Array[String]])
+		val realArray: Array[String] = arguments.toArray
+		assert(realArray.getClass eq classOf[Array[String]])
+		process.invoke(null, realArray)
+	}
+}
+/** Interface to the compiler that uses the dependency analysis plugin.*/
+class AnalyzeCompile(scalaVersion: String, scalaLoader: ClassLoader, manager: ComponentManager) extends NotNull
+{
+	def this(scalaVersion: String, provider: xsbti.ScalaProvider, manager: ComponentManager) =
+		this(scalaVersion, provider.getScalaLoader(scalaVersion), manager)
+	/** The jar containing the compiled plugin and the compiler interface code.  This will be passed to scalac as a compiler plugin
+	* and used to load the class that actually interfaces with Global.*/
+	def apply(arguments: Seq[String], callback: AnalysisCallback, maximumErrors: Int, log: Logger)
+	{
+		// this is the instance used to compile the analysis
+		val componentCompiler = new ComponentCompiler(scalaVersion, new RawCompiler(scalaLoader), manager)
+		val interfaceJar = componentCompiler(ComponentCompiler.compilerInterfaceID)
+		val argsWithPlugin = ("-Xplugin:" + interfaceJar.getAbsolutePath) :: arguments.toList
+		val dual = createDualLoader(scalaLoader, getClass.getClassLoader) // this goes to scalaLoader for scala classes and sbtLoader for xsbti classes
+		val interfaceLoader = new URLClassLoader(Array(interfaceJar.toURI.toURL), dual)
+		val interface = Class.forName("xsbt.CompilerInterface", true, interfaceLoader).newInstance
+		val runnable = interface.asInstanceOf[{ def run(args: Array[String], callback: AnalysisCallback, maximumErrors: Int, log: Logger): Unit }]
+			// these arguments are safe to pass across the ClassLoader boundary because the types are defined in Java
+		//  so they will be binary compatible across all versions of Scala
+		runnable.run(argsWithPlugin.toArray, callback, maximumErrors, log)
+	}
+	private def createDualLoader(scalaLoader: ClassLoader, sbtLoader: ClassLoader): ClassLoader =
+	{
+		val xsbtiFilter = (name: String) => name.startsWith("xsbti.")
+		val notXsbtiFilter = (name: String) => !xsbtiFilter(name)
+		new DualLoader(scalaLoader, notXsbtiFilter, x => true, sbtLoader, xsbtiFilter, x => false)
 	}
 }
\ No newline at end of file
diff --git a/compile/ComponentCompiler.scala b/compile/ComponentCompiler.scala
index c60c86253..369c0cb85 100644
--- a/compile/ComponentCompiler.scala
+++ b/compile/ComponentCompiler.scala
@@ -5,42 +5,43 @@ import java.io.File
 object ComponentCompiler
 {
 	val xsbtiID = "xsbti"
-	val compilerInterfaceID = "compilerInterface"
+	val srcExtension = "-src"
+	val binSeparator = "-bin_"
+	val compilerInterfaceID = "compiler-interface"
+	val compilerInterfaceSrcID = compilerInterfaceID + srcExtension
 }
-class ComponentCompiler(compiler: Compiler)
+class ComponentCompiler(scalaVersion: String, compiler: RawCompiler, manager: ComponentManager)
 {
-	import compiler.{manager, scalaVersion}
 	import ComponentCompiler._
-	
-	lazy val xsbtiJars = manager.files(xsbtiID)
-	
 	import FileUtilities.{copy, createDirectory, zip, jars, unzip, withTemporaryDirectory}
 	def apply(id: String): File =
 	{
-		val binID = id + "-bin_" + scalaVersion
+		val binID = binaryID(id, scalaVersion)
 		try { manager.file(binID) }
-		catch { case e: Exception => compileAndInstall(id, binID) }
+		catch { case e: InvalidComponent => compileAndInstall(id, binID) }
 	}
+	private def binaryID(id: String, scalaVersion: String) = id + binSeparator + scalaVersion
 	private def compileAndInstall(id: String, binID: String): File =
 	{
-		val srcID = id + "-src_" + scalaVersion
+		val srcID = id + srcExtension
 		val binaryDirectory = manager.location(binID)
 		createDirectory(binaryDirectory)
 		val targetJar = new File(binaryDirectory, id + ".jar")
-		compileSources(manager.files(srcID), compiler, targetJar, id)
+		compileSources(manager.files(srcID), targetJar, id)
 		manager.cache(binID)
 		targetJar
 	}
 	/** Extract sources from source jars, compile them with the xsbti interfaces on the classpath, and package the compiled classes and
 	* any resources from the source jars into a final jar.*/
-	private def compileSources(sourceJars: Iterable[File], compiler: Compiler, targetJar: File, id: String)
+	private def compileSources(sourceJars: Iterable[File], targetJar: File, id: String)
 	{
 		withTemporaryDirectory { dir =>
 			val extractedSources = (Set[File]() /: sourceJars) { (extracted, sourceJar)=> extracted ++ unzip(sourceJar, dir) }
 			val (sourceFiles, resources) = extractedSources.partition(_.getName.endsWith(".scala"))
 			withTemporaryDirectory { outputDirectory =>
+				val xsbtiJars = manager.files(xsbtiID)
 				val arguments = Seq("-d", outputDirectory.getAbsolutePath, "-cp", xsbtiJars.mkString(File.pathSeparator)) ++ sourceFiles.toSeq.map(_.getAbsolutePath)
-				compiler.raw(arguments)
+				compiler(arguments)
 				copy(resources, outputDirectory, PathMapper.relativeTo(dir))
 				zip(Seq(outputDirectory), targetJar, true, PathMapper.relativeTo(outputDirectory))
 			}
diff --git a/compile/interface/src/test/scala/TestCompile.scala b/compile/interface/src/test/scala/TestCompile.scala
index 013dd4188..fbac3521a 100644
--- a/compile/interface/src/test/scala/TestCompile.scala
+++ b/compile/interface/src/test/scala/TestCompile.scala
@@ -39,24 +39,4 @@ object CallbackTest
 			TestCompile(newArgs, superclassNames) { case (callback, log) => f(callback, outputDir, log) }
 		}
 	}
-}
-object WithFiles
-{
-	/** Takes the relative path -> content pairs and writes the content to a file in a temporary directory.  The written file
-	* path is the relative path resolved against the temporary directory path.  The provided function is called with the resolved file paths
-	* in the same order as the inputs. */
-	def apply[T](sources: (File, String)*)(f: Seq[File] => T): T =
-	{
-		withTemporaryDirectory { dir =>
-			val sourceFiles =
-				for((file, content) <- sources) yield
-				{
-					assert(!file.isAbsolute)
-					val to = new File(dir, file.getPath)
-					write(to, content)
-					to
-				}
-			f(sourceFiles)
-		}
-	}
 }
\ No newline at end of file
diff --git a/compile/src/test/scala/CompileTest.scala b/compile/src/test/scala/CompileTest.scala
new file mode 100644
index 000000000..dbb26516a
--- /dev/null
+++ b/compile/src/test/scala/CompileTest.scala
@@ -0,0 +1,50 @@
+package xsbt
+
+import java.io.File
+import FileUtilities.withTemporaryDirectory
+import org.specs._
+
+// compile w/ analysis a bit hard to test properly right now:
+//  requires compile project to depend on +publish-local, which is not possible in sbt (addressed in xsbt, but that doesn't help here!)
+object CompileTest extends Specification
+{
+	"Analysis compiler" should {
+		"compile basic sources" in {
+			TestIvyLogger { log =>
+				LoadHelpers.withLaunch { launch =>
+					val scalaVersion = "2.7.2"
+					val sbtVersion = xsbti.Versions.Sbt
+					val manager = new ComponentManager(launch.getSbtHome(sbtVersion, scalaVersion), log)
+					prepare(manager, ComponentCompiler.compilerInterfaceSrcID, "CompilerInterface.scala")
+					prepare(manager, ComponentCompiler.xsbtiID, classOf[xsbti.AnalysisCallback])
+					testCompileAnalysis(new AnalyzeCompile(scalaVersion,  launch, manager), log)
+				}
+			}
+		}
+	}
+	private def testCompileAnalysis(compiler: AnalyzeCompile, log: xsbti.Logger)
+	{
+		WithFiles( new File("Test.scala") -> "object Test" ) { sources =>
+			withTemporaryDirectory { temp =>
+				val arguments = "-d" :: temp.getAbsolutePath :: sources.map(_.getAbsolutePath).toList
+				val callback = new xsbti.TestCallback(Array())
+				compiler(arguments, callback, 10, log)
+				(callback.beganSources) must haveTheSameElementsAs(sources)
+			}
+		}
+	}
+	private def prepare(manager: ComponentManager, id: String, resource: Class[_]): Unit =
+	{
+		val src = FileUtilities.classLocationFile(resource)
+		prepare(manager, id, src)
+	}
+	private def prepare(manager: ComponentManager, id: String, resource: String): Unit =
+	{
+		val src = getClass.getClassLoader.getResource(resource)
+		if(src eq null)
+			error("Resource not found: " + resource)
+		prepare(manager, id, FileUtilities.asFile(src))
+	}
+	private def prepare(manager: ComponentManager, id: String, file: File): Unit =
+		FileUtilities.copy(Seq(file), manager.location(id), PathMapper.flat)
+}
\ No newline at end of file
diff --git a/launch/Boot.scala b/launch/Boot.scala
index fcbfb2aa1..05b94ebc5 100644
--- a/launch/Boot.scala
+++ b/launch/Boot.scala
@@ -3,7 +3,7 @@
  */
  package xsbt.boot
 
-import BootConfiguration.SbtMainClass
+import BootConfiguration.{SbtMainClass, SbtModuleName}
 import java.io.File
 
 // The entry point to the launcher
@@ -12,7 +12,7 @@ object Boot
 	def main(args: Array[String])
 	{
 		CheckProxy()
-		try { (new Launch(new File("."), SbtMainClass)).boot(args) }
+		try { Launch(args) }
 		catch
 		{
 			case b: BootException => errorAndExit(b)
diff --git a/launch/BootConfiguration.scala b/launch/BootConfiguration.scala
index 6c54a9a21..9527f5d3a 100644
--- a/launch/BootConfiguration.scala
+++ b/launch/BootConfiguration.scala
@@ -15,10 +15,11 @@ private object BootConfiguration
 
 	// these are the module identifiers to resolve/retrieve
 	val ScalaOrg = "org.scala-lang"
-	val SbtOrg = "sbt"
+	val SbtOrg = "org.scala-tools.sbt"
 	val CompilerModuleName = "scala-compiler"
 	val LibraryModuleName = "scala-library"
-	val SbtModuleName = "simple-build-tool"
+	val SbtModuleName = "xsbt"
+	val MainSbtComponentID = "default"
 
 	/** The Ivy conflict manager to use for updating.*/
 	val ConflictManagerName = "strict"
@@ -38,7 +39,7 @@ private object BootConfiguration
 	* and the project definition*/
 	val IvyPackage = "org.apache.ivy."
 	/** The class name prefix used to hide the sbt launcher classes from sbt and the project definition.
-	* Note that access to xsbti.boot classes are allowed.*/
+	* Note that access to xsbti classes are allowed.*/
 	val SbtBootPackage = "xsbt.boot."
 	/** The loader will check that these classes can be loaded and will assume that their presence indicates
 	* sbt and its dependencies have been downloaded.*/
@@ -69,7 +70,7 @@ private object BootConfiguration
 	/** The Ivy pattern to use for resolving sbt and its dependencies from the Google code project.*/
 	def sbtResolverPattern(scalaVersion: String) = sbtRootBase + "[revision]/[type]s/[artifact].[ext]"
 	/** The name of the directory to retrieve sbt and its dependencies to.*/
-	def sbtDirectoryName(sbtVersion: String) = SbtOrg + "-" + sbtVersion
+	def sbtDirectoryName(sbtVersion: String) = SbtModuleName + "-" + sbtVersion
 	/** The name of the directory in the boot directory to put all jars for the given version of scala in.*/
 	def baseDirectoryName(scalaVersion: String) = "scala-" + scalaVersion
 }
diff --git a/launch/FilteredLoader.scala b/launch/FilteredLoader.scala
index 3a3dec645..5dbcfe1e9 100644
--- a/launch/FilteredLoader.scala
+++ b/launch/FilteredLoader.scala
@@ -7,7 +7,7 @@ import BootConfiguration.{IvyPackage, SbtBootPackage, ScalaPackage}
 
 /** A custom class loader to ensure the main part of sbt doesn't load any Scala or
 * Ivy classes from the jar containing the loader. */
-private[boot] final class BootFilteredLoader extends ClassLoader with NotNull
+private[boot] final class BootFilteredLoader(parent: ClassLoader) extends ClassLoader(parent) with NotNull
 {
 	@throws(classOf[ClassNotFoundException])
 	override final def loadClass(className: String, resolve: Boolean): Class[_] =
@@ -17,4 +17,6 @@ private[boot] final class BootFilteredLoader extends ClassLoader with NotNull
 		else
 			super.loadClass(className, resolve)
 	}
+	override def getResources(name: String) = null
+	override def getResource(name: String) = null
 }
\ No newline at end of file
diff --git a/launch/Launch.scala b/launch/Launch.scala
index dc3b8489e..f7335f0cc 100644
--- a/launch/Launch.scala
+++ b/launch/Launch.scala
@@ -11,7 +11,7 @@
 import java.io.{File, FileFilter}
 import java.net.URLClassLoader
 
-import xsbti.boot.{Exit => IExit, Launcher, MainResult, Reboot, SbtConfiguration, SbtMain}
+import xsbti.{Exit => IExit, Launcher, MainResult, Reboot, SbtConfiguration, SbtMain}
 
 // contains constants and paths
 import BootConfiguration._
@@ -20,6 +20,9 @@ import UpdateTarget.{UpdateScala, UpdateSbt}
 
 class Launch(projectRootDirectory: File, mainClassName: String) extends Launcher with NotNull
 {
+	def this(projectRootDirectory: File) = this(projectRootDirectory, SbtMainClass)
+	def this() = this(new File("."))
+
 	import Launch._
 	final def boot(args: Array[String])
 	{
@@ -43,9 +46,20 @@ class Launch(projectRootDirectory: File, mainClassName: String) extends Launcher
 	* this loader from being seen by the loaded sbt/project.*/
 	def load(args: Array[String]): MainResult =
 	{
-		val (definitionScalaVersion, useSbtVersion) = ProjectProperties.forcePrompt(PropertiesFile)//, forcePrompt : _*)
-		val scalaLoader = getScalaLoader(definitionScalaVersion)
-		val sbtLoader = createSbtLoader(useSbtVersion, definitionScalaVersion, scalaLoader)
+		val (scalaVersion, sbtVersion) = ProjectProperties.forcePrompt(PropertiesFile)//, forcePrompt : _*)
+		load(args, sbtVersion, mainClassName, scalaVersion)
+	}
+	def componentLocation(sbtVersion: String, id: String, scalaVersion: String): File = new File(getSbtHome(sbtVersion, scalaVersion), id)
+	def getSbtHome(sbtVersion: String, scalaVersion: String): File =
+	{
+		val baseDirectory = new File(BootDirectory, baseDirectoryName(scalaVersion))
+		new File(baseDirectory, sbtDirectoryName(sbtVersion))
+	}
+	def getScalaHome(scalaVersion: String) = new File(new File(BootDirectory, baseDirectoryName(scalaVersion)), ScalaDirectoryName)
+
+	def load(args: Array[String], useSbtVersion: String, mainClassName: String, definitionScalaVersion: String): MainResult =
+	{
+		val sbtLoader = update(definitionScalaVersion, useSbtVersion)
 		val configuration = new SbtConfiguration
 		{
 			def arguments = args
@@ -53,15 +67,21 @@ class Launch(projectRootDirectory: File, mainClassName: String) extends Launcher
 			def sbtVersion = useSbtVersion
 			def launcher: Launcher = Launch.this
 		}
-		run(sbtLoader, configuration)
+		run(sbtLoader, mainClassName, configuration)
 	 }
-	def run(sbtLoader: ClassLoader, configuration: SbtConfiguration): MainResult =
+	def update(scalaVersion: String, sbtVersion: String): ClassLoader =
+	{
+		val scalaLoader = getScalaLoader(scalaVersion)
+		createSbtLoader(sbtVersion, scalaVersion, scalaLoader)
+	}
+	
+	def run(sbtLoader: ClassLoader, mainClassName: String, configuration: SbtConfiguration): MainResult =
 	{
 		val sbtMain = Class.forName(mainClassName, true, sbtLoader)
 		val main = sbtMain.newInstance.asInstanceOf[SbtMain]
 		main.run(configuration)
 	}
-	
+
 	final val ProjectDirectory = new File(projectRootDirectory, ProjectDirectoryName)
 	final val BootDirectory = new File(ProjectDirectory, BootDirectoryName)
 	final val PropertiesFile = new File(ProjectDirectory, BuildPropertiesName)
@@ -87,12 +107,11 @@ class Launch(projectRootDirectory: File, mainClassName: String) extends Launcher
 				Some(new Exit(1))
 		}
 	}
-	
+
 	private val scalaLoaderCache = new scala.collection.jcl.WeakHashMap[String, ClassLoader]
 	def launcher(directory: File, mainClassName: String): Launcher = new Launch(directory, mainClassName)
 	def getScalaLoader(scalaVersion: String) = scalaLoaderCache.getOrElseUpdate(scalaVersion, createScalaLoader(scalaVersion))
-	def getScalaHome(scalaVersion: String) = new File(new File(BootDirectory, baseDirectoryName(scalaVersion)), ScalaDirectoryName)
-	
+
 	def createScalaLoader(scalaVersion: String): ClassLoader =
 	{
 		val baseDirectory = new File(BootDirectory, baseDirectoryName(scalaVersion))
@@ -108,27 +127,28 @@ class Launch(projectRootDirectory: File, mainClassName: String) extends Launcher
 		else
 			scalaLoader
 	}
-	def createSbtLoader(sbtVersion: String, scalaVersion: String, scalaLoader: ClassLoader): ClassLoader =
+	def createSbtLoader(sbtVersion: String, scalaVersion: String): ClassLoader = createSbtLoader(sbtVersion, scalaVersion, getScalaLoader(scalaVersion))
+	def createSbtLoader(sbtVersion: String, scalaVersion: String, parentLoader: ClassLoader): ClassLoader =
 	{
 		val baseDirectory = new File(BootDirectory, baseDirectoryName(scalaVersion))
-		val sbtDirectory = new File(baseDirectory, sbtDirectoryName(sbtVersion))
-
-		val sbtLoader = newSbtLoader(sbtDirectory, scalaLoader)
+		val mainComponentLocation = componentLocation(sbtVersion, MainSbtComponentID, scalaVersion)
+		val sbtLoader = newSbtLoader(mainComponentLocation, parentLoader)
 		if(needsUpdate(sbtLoader, TestLoadSbtClasses))
 		{
 			(new Update(baseDirectory, sbtVersion, scalaVersion))(UpdateSbt)
-			val sbtLoader = newSbtLoader(sbtDirectory, scalaLoader)
+			val sbtLoader = newSbtLoader(mainComponentLocation, parentLoader)
 			failIfMissing(sbtLoader, TestLoadSbtClasses, "sbt " + sbtVersion)
 			sbtLoader
 		}
 		else
 			sbtLoader
 	}
-	private def newScalaLoader(dir: File) = newLoader(dir, new BootFilteredLoader)
-	private def newSbtLoader(dir: File, scalaLoader: ClassLoader) = newLoader(dir, scalaLoader)
+	private def newScalaLoader(dir: File) = newLoader(dir, new BootFilteredLoader(getClass.getClassLoader))
+	private def newSbtLoader(dir: File, parentLoader: ClassLoader) = newLoader(dir, parentLoader)
 }
 private object Launch
 {
+	def apply(args: Array[String]) = (new Launch).boot(args)
 	def isYes(so: Option[String]) = isValue("y", "yes")(so)
 	def isScratch(so: Option[String]) = isValue("s", "scratch")(so)
 	def isValue(values: String*)(so: Option[String]) =
diff --git a/launch/interface/src/main/java/xsbti/boot/Exit.java b/launch/interface/src/main/java/xsbti/Exit.java
similarity index 75%
rename from launch/interface/src/main/java/xsbti/boot/Exit.java
rename to launch/interface/src/main/java/xsbti/Exit.java
index 316fb8ee0..64e08f174 100644
--- a/launch/interface/src/main/java/xsbti/boot/Exit.java
+++ b/launch/interface/src/main/java/xsbti/Exit.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 public interface Exit extends MainResult
 {
 	public int code();
diff --git a/launch/interface/src/main/java/xsbti/Launcher.java b/launch/interface/src/main/java/xsbti/Launcher.java
new file mode 100644
index 000000000..fb7925aeb
--- /dev/null
+++ b/launch/interface/src/main/java/xsbti/Launcher.java
@@ -0,0 +1,21 @@
+package xsbti;
+
+import java.io.File;
+
+public interface Launcher extends ScalaProvider, SbtProvider
+{
+	public static final int InterfaceVersion = 1;
+
+	public void boot(String[] args);
+	public MainResult checkAndLoad(String[] args);
+	public MainResult load(String[] args);
+	public MainResult load(String[] args, String useSbtVersion, String mainClassName, String definitionScalaVersion);
+	public ClassLoader update(String scalaVersion, String sbtVersion);
+	public MainResult run(ClassLoader sbtLoader, String mainClassName, SbtConfiguration configuration);
+
+	public File ProjectDirectory();
+	public File BootDirectory();
+	public File PropertiesFile();
+
+	public Launcher launcher(File base, String mainClassName);
+}
\ No newline at end of file
diff --git a/launch/interface/src/main/java/xsbti/boot/MainResult.java b/launch/interface/src/main/java/xsbti/MainResult.java
similarity index 62%
rename from launch/interface/src/main/java/xsbti/boot/MainResult.java
rename to launch/interface/src/main/java/xsbti/MainResult.java
index e894519fa..48ea398bf 100644
--- a/launch/interface/src/main/java/xsbti/boot/MainResult.java
+++ b/launch/interface/src/main/java/xsbti/MainResult.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 
 public interface MainResult {}
 
diff --git a/launch/interface/src/main/java/xsbti/boot/Reboot.java b/launch/interface/src/main/java/xsbti/Reboot.java
similarity index 78%
rename from launch/interface/src/main/java/xsbti/boot/Reboot.java
rename to launch/interface/src/main/java/xsbti/Reboot.java
index 16c1fdc19..bc8c35709 100644
--- a/launch/interface/src/main/java/xsbti/boot/Reboot.java
+++ b/launch/interface/src/main/java/xsbti/Reboot.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 public interface Reboot extends MainResult
 {
 	public String[] arguments();
diff --git a/launch/interface/src/main/java/xsbti/boot/SbtConfiguration.java b/launch/interface/src/main/java/xsbti/SbtConfiguration.java
similarity index 88%
rename from launch/interface/src/main/java/xsbti/boot/SbtConfiguration.java
rename to launch/interface/src/main/java/xsbti/SbtConfiguration.java
index fb6859a60..d7d6e1909 100644
--- a/launch/interface/src/main/java/xsbti/boot/SbtConfiguration.java
+++ b/launch/interface/src/main/java/xsbti/SbtConfiguration.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 
 public interface SbtConfiguration
 {
diff --git a/launch/interface/src/main/java/xsbti/boot/SbtMain.java b/launch/interface/src/main/java/xsbti/SbtMain.java
similarity index 80%
rename from launch/interface/src/main/java/xsbti/boot/SbtMain.java
rename to launch/interface/src/main/java/xsbti/SbtMain.java
index 9e2e4e089..15858be5b 100644
--- a/launch/interface/src/main/java/xsbti/boot/SbtMain.java
+++ b/launch/interface/src/main/java/xsbti/SbtMain.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 
 public interface SbtMain
 {
diff --git a/launch/interface/src/main/java/xsbti/SbtProvider.java b/launch/interface/src/main/java/xsbti/SbtProvider.java
new file mode 100644
index 000000000..f5d857e5e
--- /dev/null
+++ b/launch/interface/src/main/java/xsbti/SbtProvider.java
@@ -0,0 +1,12 @@
+package xsbti;
+
+import java.io.File;
+
+public interface SbtProvider
+{
+	public ClassLoader createSbtLoader(String sbtVersion, String scalaVersion);
+	public ClassLoader createSbtLoader(String sbtVersion, String scalaVersion, ClassLoader parentLoader);
+
+	public File getSbtHome(String sbtVersion, String scalaVersion);
+	public File componentLocation(String sbtVersion, String id, String scalaVersion);
+}
\ No newline at end of file
diff --git a/launch/interface/src/main/java/xsbti/boot/ScalaProvider.java b/launch/interface/src/main/java/xsbti/ScalaProvider.java
similarity index 88%
rename from launch/interface/src/main/java/xsbti/boot/ScalaProvider.java
rename to launch/interface/src/main/java/xsbti/ScalaProvider.java
index 3567d691e..bd780eac7 100644
--- a/launch/interface/src/main/java/xsbti/boot/ScalaProvider.java
+++ b/launch/interface/src/main/java/xsbti/ScalaProvider.java
@@ -1,4 +1,4 @@
-package xsbti.boot;
+package xsbti;
 
 import java.io.File;
 
diff --git a/launch/interface/src/main/java/xsbti/boot/Launcher.java b/launch/interface/src/main/java/xsbti/boot/Launcher.java
deleted file mode 100644
index 7a4c97351..000000000
--- a/launch/interface/src/main/java/xsbti/boot/Launcher.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package xsbti.boot;
-
-import java.io.File;
-
-public interface Launcher extends ScalaProvider
-{
-	public static final int InterfaceVersion = 1;
-	
-	public void boot(String[] args);
-	public MainResult checkAndLoad(String[] args);
-	public MainResult load(String[] args);
-	public MainResult run(ClassLoader sbtLoader, SbtConfiguration configuration);
-	
-	public File ProjectDirectory();
-	public File BootDirectory();
-	public File PropertiesFile();
-	
-	public Launcher launcher(File base, String mainClassName);
-}
\ No newline at end of file
diff --git a/launch/src/test/scala/ScalaProviderTest.scala b/launch/src/test/scala/ScalaProviderTest.scala
index 32cc3a7b4..a66aaf2ca 100644
--- a/launch/src/test/scala/ScalaProviderTest.scala
+++ b/launch/src/test/scala/ScalaProviderTest.scala
@@ -1,28 +1,84 @@
 package xsbt
 
 import java.util.Properties
-import xsbti.boot._
+import xsbti._
 import org.specs._
+import LoadHelpers._
+
+final class Main // needed so that when we test Launch, it doesn't think sbt was improperly downloaded (it looks for xsbt.Main to verify the right jar was downloaded)
 
 object ScalaProviderTest extends Specification
 {
-	"Launch" should {
-		"Provide ClassLoader for Scala 2.7.2" in { checkScalaLoader("2.7.2", "2.7.2") }
-		"Provide ClassLoader for Scala 2.7.3" in { checkScalaLoader("2.7.3", "2.7.3.final") }
-		"Provide ClassLoader for Scala 2.7.4" in { checkScalaLoader("2.7.4", "2.7.4.final") }
-		"Provide ClassLoader for Scala 2.7.5" in { checkScalaLoader("2.7.5", "2.7.5.final") }
+	 def provide = addToSusVerb("provide")
+	"Launch" should provide {
+		"ClassLoader for Scala 2.7.2" in { checkScalaLoader("2.7.2") }
+		"ClassLoader for Scala 2.7.3" in { checkScalaLoader("2.7.3") }
+		"ClassLoader for Scala 2.7.4" in { checkScalaLoader("2.7.4") }
+		"ClassLoader for Scala 2.7.5" in { checkScalaLoader("2.7.5") }
 	}
-	private def checkScalaLoader(version: String, versionValue: String): Unit = withLaunch(checkLauncher(version, versionValue))
-	private def checkLauncher(version: String, versionValue: String)(launcher: Launcher): Unit =
+
+	"Launch" should {
+		"Successfully load (stub) main sbt from local repository and run it with correct arguments" in {
+			checkLoad(Array("test"), "xsbt.test.ArgumentTest").asInstanceOf[Exit].code must be(0)
+			checkLoad(Array(), "xsbt.test.ArgumentTest") must throwA[RuntimeException]
+		}
+		"Successfully load (stub) main sbt from local repository and run it with correct sbt version" in {
+			checkLoad(Array(), "xsbt.test.SbtVersionTest").asInstanceOf[Exit].code must be(0)
+		}
+	}
+
+	private def checkLoad(args: Array[String], mainClassName: String): MainResult =
+		withLaunch { _.load(args, test.MainTest.SbtTestVersion, mainClassName, mapScalaVersion(getScalaVersion)) }
+
+	private def checkScalaLoader(version: String): Unit = withLaunch(checkLauncher(version, scalaVersionMap(version)))
+	private def checkLauncher(version: String, versionValue: String)(launcher: ScalaProvider): Unit =
 	{
 		val loader = launcher.getScalaLoader(version)
-		Class.forName("scala.ScalaObject", false, loader)
+		// ensure that this loader can load Scala classes by trying scala.ScalaObject.
+		tryScala(loader)
+		getScalaVersion(loader) must beEqualTo(versionValue)
+	}
+	private def tryScala(loader: ClassLoader): Unit = Class.forName("scala.ScalaObject", false, loader).getClassLoader must be(loader)
+}
+object LoadHelpers
+{
+	def withLaunch[T](f: Launcher => T): T =
+		FileUtilities.withTemporaryDirectory { temp => f(new xsbt.boot.Launch(temp)) }
+	def mapScalaVersion(versionNumber: String) = scalaVersionMap.find(_._2 == versionNumber).getOrElse {
+		error("Scala version number " + versionNumber + " from library.properties has no mapping")}._1
+	val scalaVersionMap = Map("2.7.2" -> "2.7.2") ++ Seq("2.7.3", "2.7.4", "2.7.5").map(v => (v, v + ".final"))
+	def getScalaVersion: String = getScalaVersion(getClass.getClassLoader)
+	def getScalaVersion(loader: ClassLoader): String =
+	{
 		val propertiesStream = loader.getResourceAsStream("library.properties")
 		val properties = new Properties
 		properties.load(propertiesStream)
-		properties.getProperty("version.number") must beEqualTo(versionValue)
+		properties.getProperty("version.number")
 	}
-	private def withLaunch[T](f: Launcher => T): T = withLaunch("")(f)
-	private def withLaunch[T](mainClass: String)(f: Launcher => T): T =
-		FileUtilities.withTemporaryDirectory { temp => f(new xsbt.boot.Launch(temp, mainClass)) }
-}
\ No newline at end of file
+}
+
+package test
+{
+	object MainTest
+	{
+		val SbtTestVersion = "test-0.7" // keep in sync with LauncherProject in the XSbt project definition
+	}
+	import MainTest.SbtTestVersion
+	final class MainException(message: String) extends RuntimeException(message)
+	final class ArgumentTest extends SbtMain
+	{
+		def run(configuration: SbtConfiguration) =
+			if(configuration.arguments.length == 0)
+				throw new MainException("Arguments were empty")
+			else
+				new xsbt.boot.Exit(0)
+	}
+	class SbtVersionTest extends SbtMain
+	{
+		def run(configuration: SbtConfiguration) =
+			if(configuration.sbtVersion == SbtTestVersion)
+				new xsbt.boot.Exit(0)
+			else
+				throw new MainException("sbt version was " + configuration.sbtVersion + ", expected: " + SbtTestVersion)
+	}
+}
diff --git a/notes b/notes
index 667d46c6d..74d4cd11e 100644
--- a/notes
+++ b/notes
@@ -19,9 +19,8 @@ Task engine
 - use Exceptions instead of Option/Either
 - every component gets its own subproject
 - can use any version of compiler/Scala that is source compatible
- - requires CrossLogger that can interface across ClassLoader boundaries with reflection
 - Logger passed by implicit parameter
-- build using normal cross-build conventions
+- build xsbt using normal cross-build conventions
 - compiler: raw interface (no dependency analysis) or with dependency analysis
 - compiler: can specify scala-library.jar and scala-compiler.jar + version instead of retrieving the ClassLoader
 - minimal dependence on main xsbt logger from subcomponents: use thin interface for subcomponents and implement interface in separate files in main xsbt
@@ -33,7 +32,7 @@ Dependency Management
 
 
 TODO:
-compiler analysis callback does not check classes against output directory.  This must now be done in callback itself:
+compiler analysis plugin does not check classes against output directory.  This must now be done in the callback itself. The old code was:
 
 		Path.relativize(outputPath, pf.file) match
 		{
diff --git a/project/build/XSbt.scala b/project/build/XSbt.scala
index ccfa445ef..212e721d0 100644
--- a/project/build/XSbt.scala
+++ b/project/build/XSbt.scala
@@ -2,36 +2,43 @@ import sbt._
 
 class XSbt(info: ProjectInfo) extends ParentProject(info)
 {
-	val testDeps = project("test-dependencies", "Dependencies", new TestDependencies(_))
-	
-	val launchInterfaceSub = project(launchPath / "interface", "Launcher Interface", new InterfaceProject(_), testDeps)
+	val launchInterfaceSub = project(launchPath / "interface", "Launcher Interface", new InterfaceProject(_))
 	val launchSub = project(launchPath, "Launcher", new LaunchProject(_), launchInterfaceSub)
 
 	val interfaceSub = project("interface", "Interface", new InterfaceProject(_))
 
 	val controlSub = project(utilPath / "control", "Control", new Base(_))
 	val collectionSub = project(utilPath / "collection", "Collections", new Base(_))
-	val ioSub = project(utilPath / "io", "IO", new Base(_), controlSub, testDeps)
+	val ioSub = project(utilPath / "io", "IO", new IOProject(_), controlSub)
 	val classpathSub = project(utilPath / "classpath", "Classpath", new Base(_))
 
-	val compilerInterfaceSub = project(compilePath / "interface", "Compiler Interface", new CompilerInterfaceProject(_), interfaceSub)
+	val compileInterfaceSub = project(compilePath / "interface", "Compiler Interface Src", new CompilerInterfaceProject(_), interfaceSub)
 
 	val ivySub = project("ivy", "Ivy", new IvyProject(_), interfaceSub)
 	val logSub = project(utilPath / "log", "Logging", new Base(_))
 
-	val taskSub = project("tasks", "Tasks", new TaskProject(_), controlSub, collectionSub, testDeps)
+	val taskSub = project("tasks", "Tasks", new TaskProject(_), controlSub, collectionSub)
 	val cacheSub = project("cache", "Cache", new CacheProject(_), taskSub, ioSub)
-	val compilerSub = project(compilePath, "Compile", new Base(_), interfaceSub, ivySub, ioSub, compilerInterfaceSub)
+	val compilerSub = project(compilePath, "Compile", new CompileProject(_),
+		launchInterfaceSub, interfaceSub, ivySub, ioSub, classpathSub, compileInterfaceSub)
 
 	def launchPath = path("launch")
 	def utilPath = path("util")
 	def compilePath = path("compile")
 
-	class LaunchProject(info: ProjectInfo) extends Base(info) with TestWithIO
+	class LaunchProject(info: ProjectInfo) extends Base(info) with TestWithIO with TestDependencies
 	{
 		val ivy = "org.apache.ivy" % "ivy" % "2.0.0"
+		// to test the retrieving and loading of the main sbt, we package and publish the test classes to the local repository
+		override def defaultMainArtifact = Artifact(idWithVersion)
+		override def projectID = ModuleID(organization, idWithVersion, "test-" + version)
+		override def packageAction = packageTask(packageTestPaths, outputPath / (idWithVersion + "-" + projectID.revision +".jar"), packageOptions).dependsOn(rawTestCompile)
+		override def deliverProjectDependencies = Nil
+		def idWithVersion = "xsbt_" + ScalaVersion.currentString
+		lazy val rawTestCompile = super.testCompileAction
+		override def testCompileAction = publishLocal dependsOn(rawTestCompile)
 	}
-	class TestDependencies(info: ProjectInfo) extends DefaultProject(info)
+	trait TestDependencies extends Project
 	{
 		val sc = "org.scala-tools.testing" % "scalacheck" % "1.5" % "test->default"
 		val sp = "org.scala-tools.testing" % "specs" % "1.5.0" % "test->default"
@@ -39,28 +46,36 @@ class XSbt(info: ProjectInfo) extends ParentProject(info)
 	}
 
 	override def parallelExecution = true
-	class TaskProject(info: ProjectInfo) extends Base(info)
+	class IOProject(info: ProjectInfo) extends Base(info) with TestDependencies
+	class TaskProject(info: ProjectInfo) extends Base(info) with TestDependencies
 	class CacheProject(info: ProjectInfo) extends Base(info)
 	{
 		//override def compileOptions = super.compileOptions ++ List(Unchecked,ExplainTypes, CompileOption("-Xlog-implicits"))
 	}
-	class Base(info: ProjectInfo) extends DefaultProject(info)
+	class Base(info: ProjectInfo) extends DefaultProject(info) with ManagedBase
 	{
 		override def scratch = true
 	}
+	class CompileProject(info: ProjectInfo) extends Base(info)
+	{
+		override def testCompileAction = super.testCompileAction dependsOn(launchSub.testCompile, compileInterfaceSub.`package`, interfaceSub.`package`)
+		override def deliverProjectDependencies = Set(super.deliverProjectDependencies.toSeq : _*) - launchInterfaceSub.projectID
+		override def testClasspath = super.testClasspath +++ launchSub.testClasspath +++ compileInterfaceSub.jarPath +++ interfaceSub.jarPath
+		override def compileOptions = super.compileOptions ++ Seq(CompileOption("-Xno-varargs-conversion"))
+	}
 	class IvyProject(info: ProjectInfo) extends Base(info) with TestWithIO
 	{
 		val ivy = "org.apache.ivy" % "ivy" % "2.0.0"
 	}
-	class InterfaceProject(info: ProjectInfo) extends DefaultProject(info)
+	class InterfaceProject(info: ProjectInfo) extends DefaultProject(info) with ManagedBase
 	{
 		override def mainSources = descendents(mainSourceRoots, "*.java")
 		override def compileOrder = CompileOrder.JavaThenScala
 	}
 	class CompilerInterfaceProject(info: ProjectInfo) extends Base(info) with SourceProject
 	{
-		// these set up the test so that the classes and resources are both in the output resource directory
-		// the main output path is removed so that the plugin (xsbt.Analyzer) is found in the output resource directory so that
+		// these set up the test environment so that the classes and resources are both in the output resource directory
+		// the main compile path is removed so that the plugin (xsbt.Analyzer) is found in the output resource directory so that
 		// the tests can configure that directory as -Xpluginsdir (which requires the scalac-plugin.xml and the classes to be together)
 		override def testCompileAction = super.testCompileAction dependsOn(packageForTest, ioSub.testCompile)
 		override def mainResources = super.mainResources +++ "scalac-plugin.xml"
@@ -77,5 +92,15 @@ class XSbt(info: ProjectInfo) extends ParentProject(info)
 }
 trait SourceProject extends BasicScalaProject
 {
-	override def packagePaths = packageSourcePaths
+	override final def crossScalaVersions = Set.empty
+	override def packagePaths = mainResources +++ mainSources
+}
+trait ManagedBase extends BasicScalaProject
+{
+	override def deliverScalaDependencies = Nil
+	override def crossScalaVersions = Set("2.7.5")
+	override def managedStyle = ManagedStyle.Ivy
+	override def useDefaultConfigurations = false
+	val defaultConf = Configurations.Default
+	val testConf = Configurations.Test
 }
\ No newline at end of file
diff --git a/util/classpath/DualLoader.scala b/util/classpath/DualLoader.scala
new file mode 100644
index 000000000..ca679045a
--- /dev/null
+++ b/util/classpath/DualLoader.scala
@@ -0,0 +1,80 @@
+package xsbt
+
+import java.net.URL
+import java.util.Enumeration
+
+class DifferentLoaders(message: String, val loaderA: ClassLoader, val loaderB: ClassLoader) extends ClassNotFoundException(message)
+class DualLoader(parentA: ClassLoader, aOnlyClasses: String => Boolean, aOnlyResources: String => Boolean,
+	parentB: ClassLoader, bOnlyClasses: String => Boolean, bOnlyResources: String => Boolean) extends ClassLoader
+{
+	def this(parentA: ClassLoader, aOnly: String => Boolean, parentB: ClassLoader, bOnly: String => Boolean) =
+		this(parentA, aOnly, aOnly, parentB, bOnly, bOnly)
+	override final def loadClass(className: String, resolve: Boolean): Class[_] =
+	{
+		val c =
+			if(aOnlyClasses(className))
+				parentA.loadClass(className)
+			else if(bOnlyClasses(className))
+				parentB.loadClass(className)
+			else
+			{
+				val classA = parentA.loadClass(className)
+				val classB = parentB.loadClass(className)
+				if(classA.getClassLoader eq classB.getClassLoader)
+					classA
+				else
+					throw new DifferentLoaders("Parent class loaders returned different classes for '" + className + "'", classA.getClassLoader, classB.getClassLoader)
+			}
+		if(resolve)
+			resolveClass(c)
+		c
+	}
+	override def getResource(name: String): URL =
+	{
+		if(aOnlyResources(name))
+			parentA.getResource(name)
+		else if(bOnlyResources(name))
+			parentB.getResource(name)
+		else
+		{
+			val urlA = parentA.getResource(name)
+			val urlB = parentB.getResource(name)
+			if(urlA eq null)
+				urlB
+			else
+				urlA
+		}
+	}
+	override def getResources(name: String): Enumeration[URL] =
+	{
+		if(aOnlyResources(name))
+			parentA.getResources(name)
+		else if(bOnlyResources(name))
+			parentB.getResources(name)
+		else
+		{
+			val urlsA = parentA.getResources(name)
+			val urlsB = parentB.getResources(name)
+			if(urlsA eq null)
+				urlsB
+			else if(urlsB eq null)
+				urlsA
+			else
+				new DualEnumeration(urlsA, urlsB)
+		}
+	}
+}
+
+final class DualEnumeration[T](a: Enumeration[T], b: Enumeration[T]) extends Enumeration[T]
+{
+	// invariant: current.hasMoreElements or current eq b
+	private[this] var current = if(a.hasMoreElements) a else b
+	def hasMoreElements = current.hasMoreElements
+	def nextElement =
+	{
+		val element = current.nextElement
+		if(!current.hasMoreElements)
+			current = b
+		element
+	}
+}
\ No newline at end of file
diff --git a/util/io/FileUtilities.scala b/util/io/FileUtilities.scala
index 739a0c2e6..7458c4069 100644
--- a/util/io/FileUtilities.scala
+++ b/util/io/FileUtilities.scala
@@ -7,7 +7,7 @@ import OpenResource._
 import ErrorHandling.translate
 
 import java.io.{File, FileInputStream, InputStream, OutputStream}
-import java.net.{URISyntaxException, URL}
+import java.net.{URI, URISyntaxException, URL}
 import java.nio.charset.Charset
 import java.util.jar.{Attributes, JarEntry, JarFile, JarInputStream, JarOutputStream, Manifest}
 import java.util.zip.{GZIPOutputStream, ZipEntry, ZipFile, ZipInputStream, ZipOutputStream}
@@ -38,6 +38,20 @@ object FileUtilities
 	def toFile(url: URL) =
 		try { new File(url.toURI) }
 		catch { case _: URISyntaxException => new File(url.getPath) }
+		
+	/** Converts the given URL to a File.  If the URL is for an entry in a jar, the File for the jar is returned. */
+	def asFile(url: URL): File =
+	{
+		url.getProtocol match
+		{
+			case "file" => toFile(url)
+			case "jar" =>
+				val path = url.getPath
+				val end = path.indexOf('!')
+				new File(new URI(if(end == -1) path else path.substring(0, end)))
+			case _ => error("Invalid protocol " + url.getProtocol)
+		}
+	}
 
 
 	// "base.extension" -> (base, extension)
diff --git a/util/io/PathMapper.scala b/util/io/PathMapper.scala
index 4112701ff..2f8afdc09 100644
--- a/util/io/PathMapper.scala
+++ b/util/io/PathMapper.scala
@@ -14,6 +14,8 @@ object PathMapper
 {
 	val basic = new FMapper(_.getPath)
 	def relativeTo(base: File) = new FMapper(file => FileUtilities.relativize(base, file).getOrElse(file.getPath))
+	val flat = new FMapper(_.getName)
+	def apply(f: File => String) = new FMapper(f)
 }
 class FMapper(f: File => String) extends PathMapper
 {
diff --git a/util/io/src/test/scala/WithFiles.scala b/util/io/src/test/scala/WithFiles.scala
new file mode 100644
index 000000000..649f96175
--- /dev/null
+++ b/util/io/src/test/scala/WithFiles.scala
@@ -0,0 +1,25 @@
+package xsbt
+
+import java.io.File
+import FileUtilities.{withTemporaryDirectory, write}
+
+object WithFiles
+{
+	/** Takes the relative path -> content pairs and writes the content to a file in a temporary directory.  The written file
+	* path is the relative path resolved against the temporary directory path.  The provided function is called with the resolved file paths
+	* in the same order as the inputs. */
+	def apply[T](sources: (File, String)*)(f: Seq[File] => T): T =
+	{
+		withTemporaryDirectory { dir =>
+			val sourceFiles =
+				for((file, content) <- sources) yield
+				{
+					assert(!file.isAbsolute)
+					val to = new File(dir, file.getPath)
+					write(to, content)
+					to
+				}
+			f(sourceFiles)
+		}
+	}
+}
\ No newline at end of file