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package ch.jodersky.jni
import macrocompat.bundle
import util.PlatformMacros
import scala.language.experimental.macros
import scala.reflect.macros.whitebox.Context
import scala.annotation.StaticAnnotation
import scala.annotation.compileTimeOnly
@bundle
class nativeLoaderMacro(val c: Context) {
def impl(annottees: c.Expr[Any]*): c.Expr[Any] = {
import c.universe._
val nativeLibrary: String = c.prefix.tree match {
case Apply(_, List(Literal(Constant(x: String)))) => x
case Apply(_, xs :: tail) => c.abort(xs.pos, "Native library must be a constant.")
case t => c.abort(t.pos, "Native library not specified.")
}
def inject(annottees: List[Tree]): List[Tree] = annottees match {
case ClassDef(mods, name, tparams, Template(parents, self, body)) :: tail =>
val extra = q"""
{
${name.toTermName}
}
"""
val module: List[Tree] = tail match {
case Nil => inject(List(q"""object ${name.toTermName}"""))
case other => inject(other)
}
ClassDef(mods, name, tparams, Template(parents, self, body :+ extra)) :: module
//q"$mods object $name extends ..$parents {$self => ..$body }" :: Nil =>
case ModuleDef(mods, name, Template(parents, self, body)) :: Nil =>
val extra = q"""{
def loadPackaged(): Unit = {
import java.io.File
import java.nio.file.{Files, Path}
val lib: String = System.mapLibraryName($nativeLibrary)
val tmp: Path = Files.createTempDirectory("jni-")
val plat: String = ${PlatformMacros.current(c)}
val resourcePath: String = "/native/" + plat + "/" + lib
val resourceStream = Option($name.getClass.getResourceAsStream(resourcePath)) match {
case Some(s) => s
case None => throw new UnsatisfiedLinkError(
"Native library " + lib + " (" + resourcePath + ") cannot be found on the classpath.")
}
val extractedPath = tmp.resolve(lib)
try {
Files.copy(resourceStream, extractedPath)
} catch {
case ex: Exception => throw new UnsatisfiedLinkError(
"Error while extracting native library: " + ex)
}
System.load(extractedPath.toAbsolutePath.toString)
}
def load(): Unit = try {
System.loadLibrary($nativeLibrary)
} catch {
case ex: UnsatisfiedLinkError => loadPackaged()
}
load()
}"""
ModuleDef(mods, name, Template(parents, self, body :+ extra)) :: Nil
case _ =>
c.abort(c.enclosingPosition, "nativeLoader can only be annotated to classes and singleton objects")
}
val outputs = inject(annottees.map(_.tree).toList)
val result: Tree = Block(outputs, Literal(Constant(())))
c.Expr[Any](result)
}
}
@compileTimeOnly("Macro Paradise must be enabled to apply annotation.")
class nativeLoader(nativeLibrary: String) extends StaticAnnotation {
def macroTransform(annottees: Any*): Any = macro nativeLoaderMacro.impl
}
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