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package scala.reflect
package runtime
import scala.tools.nsc.reporters.Reporter
import scala.tools.nsc.reporters.StoreReporter
import scala.tools.nsc.reporters.AbstractReporter
import scala.tools.nsc.ReflectGlobal
import scala.tools.nsc.CompilerCommand
import scala.tools.nsc.Global
import scala.tools.nsc.typechecker.Modes
import scala.tools.nsc.io.VirtualDirectory
import scala.tools.nsc.interpreter.AbstractFileClassLoader
import reflect.{mirror => rm}
import scala.tools.nsc.util.FreshNameCreator
import scala.reflect.internal.Flags
import scala.tools.nsc.util.{NoSourceFile, NoFile}
import java.lang.{Class => jClass}
import scala.tools.nsc.util.trace
trait ToolBoxes extends { self: Universe =>
class ToolBox(val reporter: Reporter = new StoreReporter, val options: String = "") {
class ToolBoxGlobal(settings: scala.tools.nsc.Settings, reporter: scala.tools.nsc.reporters.Reporter)
extends ReflectGlobal(settings, reporter) {
import definitions._
private val trace = scala.tools.nsc.util.trace when settings.debug.value
private final val wrapperMethodName = "wrapper"
private var wrapCount = 0
private def nextWrapperModuleName() = {
wrapCount += 1
newTermName("__wrapper$" + wrapCount)
}
private def moduleFileName(className: String) = className + "$"
private def isFree(t: Tree) = t.isInstanceOf[Ident] && t.symbol.isInstanceOf[FreeVar]
def typedTopLevelExpr(tree: Tree, pt: Type): Tree = {
// !!! Why is this is in the empty package? If it's only to make
// it inaccessible then please put it somewhere designed for that
// rather than polluting the empty package with synthetics.
trace("typing: ")(showAttributed(tree, true, true, settings.Yshowsymkinds.value))
val ownerClass = EmptyPackageClass.newClassWithInfo(newTypeName("<expression-owner>"), List(ObjectClass.tpe), newScope)
val owner = ownerClass.newLocalDummy(tree.pos)
val ttree = typer.atOwner(tree, owner).typed(tree, analyzer.EXPRmode, pt)
trace("typed: ")(showAttributed(ttree, true, true, settings.Yshowsymkinds.value))
ttree
}
def defOwner(tree: Tree): Symbol = tree find (_.isDef) map (_.symbol) match {
case Some(sym) if sym != null && sym != NoSymbol => sym.owner
case _ => NoSymbol
}
def wrapInObject(expr: Tree, fvs: List[Symbol]): ModuleDef = {
val obj = EmptyPackageClass.newModule(nextWrapperModuleName())
val minfo = ClassInfoType(List(ObjectClass.tpe, ScalaObjectClass.tpe), newScope, obj.moduleClass)
obj.moduleClass setInfo minfo
obj setInfo obj.moduleClass.tpe
val meth = obj.moduleClass.newMethod(newTermName(wrapperMethodName))
def makeParam(fv: Symbol) = meth.newValueParameter(fv.name.toTermName) setInfo fv.tpe
meth setInfo MethodType(fvs map makeParam, AnyClass.tpe)
minfo.decls enter meth
trace("wrapping ")(defOwner(expr) -> meth)
val methdef = DefDef(meth, expr changeOwner (defOwner(expr) -> meth))
val moduledef = ModuleDef(
obj,
Template(
List(TypeTree(ObjectClass.tpe)),
emptyValDef,
NoMods,
List(),
List(List()),
List(methdef),
NoPosition))
trace("wrapped: ")(showAttributed(moduledef, true, true, settings.Yshowsymkinds.value))
val cleanedUp = resetLocalAttrs(moduledef)
trace("cleaned up: ")(showAttributed(cleanedUp, true, true, settings.Yshowsymkinds.value))
cleanedUp
}
def wrapInPackage(clazz: Tree): PackageDef =
PackageDef(Ident(nme.EMPTY_PACKAGE_NAME), List(clazz))
def wrapInCompilationUnit(tree: Tree): CompilationUnit = {
val unit = new CompilationUnit(NoSourceFile)
unit.body = tree
unit
}
def compileExpr(expr: Tree, fvs: List[Symbol]): String = {
// Previously toolboxes used to typecheck their inputs before compiling.
// Actually, the initial demo by Martin first typechecked the reified tree,
// then ran it, which typechecked it again, and only then launched the
// reflective compiler.
//
// However, as observed in https://issues.scala-lang.org/browse/SI-5464
// current implementation typechecking is not always idempotent.
// That's why we cannot allow inputs of toolboxes to be typechecked,
// at least not until the aforementioned issue is closed.
val typed = expr filter (t => t.tpe != null && t.tpe != NoType && !t.isInstanceOf[TypeTree])
if (!typed.isEmpty) {
throw new Error("cannot compile trees that are already typed")
}
val mdef = wrapInObject(expr, fvs)
val pdef = wrapInPackage(mdef)
val unit = wrapInCompilationUnit(pdef)
val run = new Run
run.compileUnits(List(unit), run.namerPhase)
mdef.symbol.fullName
}
private def getMethod(jclazz: jClass[_], name: String) =
jclazz.getDeclaredMethods.find(_.getName == name).get
def runExpr(expr: Tree): Any = {
val fvs = (expr filter isFree map (_.symbol)).distinct
reporter.reset()
val className = compileExpr(expr, fvs)
if (reporter.hasErrors) {
throw new Error("reflective compilation has failed")
}
if (settings.debug.value) println("generated: "+className)
val jclazz = jClass.forName(moduleFileName(className), true, classLoader)
val jmeth = jclazz.getDeclaredMethods.find(_.getName == wrapperMethodName).get
val jfield = jclazz.getDeclaredFields.find(_.getName == NameTransformer.MODULE_INSTANCE_NAME).get
val singleton = jfield.get(null)
// @odersky writes: Not sure we will be able to drop this. I forgot the reason why we dereference () functions,
// but there must have been one. So I propose to leave old version in comments to be resurrected if the problem resurfaces.
// val result = jmeth.invoke(singleton, fvs map (sym => sym.asInstanceOf[FreeVar].value.asInstanceOf[AnyRef]): _*)
// if (etpe.typeSymbol != FunctionClass(0)) result
// else {
// val applyMeth = result.getClass.getMethod("apply")
// applyMeth.invoke(result)
// }
jmeth.invoke(singleton, fvs map (sym => sym.asInstanceOf[FreeVar].value.asInstanceOf[AnyRef]): _*)
}
def showAttributed(tree: Tree, printTypes: Boolean = true, printIds: Boolean = true, printKinds: Boolean = false): String = {
val saved1 = settings.printtypes.value
val saved2 = settings.uniqid.value
val saved3 = settings.Yshowsymkinds.value
try {
settings.printtypes.value = printTypes
settings.uniqid.value = printIds
settings.Yshowsymkinds.value = printKinds
tree.toString
} finally {
settings.printtypes.value = saved1
settings.uniqid.value = saved2
settings.Yshowsymkinds.value = saved3
}
}
}
lazy val arguments = options.split(" ")
lazy val virtualDirectory =
(arguments zip arguments.tail) collect { case ("-d", dir) => dir } lastOption match {
case Some(outDir) => scala.tools.nsc.io.AbstractFile.getDirectory(outDir)
case None => new VirtualDirectory("(memory)", None)
}
lazy val compiler: ToolBoxGlobal = {
val errorFn: String => Unit = reporter.error(scala.tools.nsc.util.NoPosition, _)
val command = reporter match {
case reporter: AbstractReporter => new CompilerCommand(arguments.toList, reporter.settings, errorFn)
case _ => new CompilerCommand(arguments.toList, errorFn)
}
command.settings.outputDirs setSingleOutput virtualDirectory
val instance = new ToolBoxGlobal(command.settings, reporter)
// need to establish a run an phase because otherwise we run into an assertion in TypeHistory
// that states that the period must be different from NoPeriod
val run = new instance.Run
instance.phase = run.refchecksPhase
instance
}
lazy val importer = new compiler.Importer {
val from: self.type = self
}
lazy val exporter = importer.reverse
lazy val classLoader = new AbstractFileClassLoader(virtualDirectory, defaultReflectiveClassLoader)
def typeCheck(tree: rm.Tree, expectedType: rm.Type): rm.Tree = {
if (compiler.settings.verbose.value) println("typing "+tree+", pt = "+expectedType)
val ctree: compiler.Tree = importer.importTree(tree.asInstanceOf[Tree])
val pt: compiler.Type = importer.importType(expectedType.asInstanceOf[Type])
val ttree: compiler.Tree = compiler.typedTopLevelExpr(ctree, pt)
val rmttree = exporter.importTree(ttree).asInstanceOf[rm.Tree]
rmttree
}
def typeCheck(tree: rm.Tree): rm.Tree =
typeCheck(tree, WildcardType.asInstanceOf[rm.Type])
def showAttributed(tree: rm.Tree, printTypes: Boolean = true, printIds: Boolean = true, printKinds: Boolean = false): String =
compiler.showAttributed(importer.importTree(tree.asInstanceOf[Tree]), printTypes, printIds, printKinds)
def runExpr(tree: rm.Tree): Any = {
if (compiler.settings.verbose.value) println("running "+tree)
val ctree: compiler.Tree = importer.importTree(tree.asInstanceOf[Tree])
compiler.runExpr(ctree)
}
}
}
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