class loader extension to handle native libraries loaded in multiple class loaders

util/classpath/ClassLoaders.scala

@@ -128,4 +128,35 @@ private object Loaders
 	def isNestedOrSelf(className: String, checkAgainst: String) =
 		className == checkAgainst || className.startsWith(checkAgainst + "$")
 	def isSbtClass(className: String) = className.startsWith(Loaders.SbtPackage)
+}
+
+final class NativeCopyConfig(val tempDirectory: File, val explicitLibraries: Seq[File], val searchPaths: Seq[File])
+trait NativeCopyLoader extends ClassLoader
+{
+	protected val config: NativeCopyConfig
+	import config._
+	
+	private[this] val mapped = new collection.mutable.HashMap[String, String]
+
+	override protected def findLibrary(name: String): String =
+		synchronized { mapped.getOrElseUpdate(name, findLibrary0(name)) }
+
+	private[this] def findLibrary0(name: String): String =
+	{
+		val mappedName = System.mapLibraryName(name)
+		val explicit = explicitLibraries.filter(_.getName == mappedName).toStream
+		val search = searchPaths.toStream flatMap relativeLibrary(mappedName)
+		(explicit ++ search).headOption.map(copy).orNull
+	}
+	private[this] def relativeLibrary(mappedName: String)(base: File): Seq[File] =
+	{
+		val f = new File(base, mappedName)
+		if(f.isFile) f :: Nil else Nil
+	}
+	private[this] def copy(f: File): String =
+	{
+		val target = new File(tempDirectory, f.getName)
+		IO.copyFile(f, target)
+		target.getAbsolutePath
+	}
 }

util/classpath/ClasspathUtilities.scala

@@ -22,7 +22,13 @@ object ClasspathUtilities
 
 	def toLoader(paths: Seq[File], parent: ClassLoader, resourceMap: Map[String,String]): ClassLoader =
 		new URLClassLoader(Path.toURLs(paths), parent) with RawResources { override def resources = resourceMap }
-	
+
+	def toLoader(paths: Seq[File], parent: ClassLoader, resourceMap: Map[String,String], nativeTemp: File): ClassLoader =
+		new URLClassLoader(Path.toURLs(paths), parent) with RawResources with NativeCopyLoader {
+			override def resources = resourceMap
+			override val config = new NativeCopyConfig(nativeTemp, paths, Nil)
+		}
+
 	lazy val rootLoader =
 	{
 		def parent(loader: ClassLoader): ClassLoader =
@@ -50,6 +56,9 @@ object ClasspathUtilities
 
 	def makeLoader[T](classpath: Seq[File], parent: ClassLoader, instance: ScalaInstance): ClassLoader =
 		toLoader(classpath, parent, createClasspathResources(classpath, instance))
+
+	def makeLoader[T](classpath: Seq[File], parent: ClassLoader, instance: ScalaInstance, nativeTemp: File): ClassLoader =
+		toLoader(classpath, parent, createClasspathResources(classpath, instance), nativeTemp)
 	
 	private[sbt] def printSource(c: Class[_]) =
 		println(c.getName + " loader=" +c.getClassLoader + " location=" + IO.classLocationFile(c))