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/* NSC -- new Scala compiler
* Copyright 2005-2007 LAMP/EPFL
* @author Gilles Dubochet
*/
// $Id$
package scala.tools.nsc.transform
import symtab._
import Flags._
import symtab.Flags._
import scala.collection.immutable.ListMap
import scala.collection.mutable.{HashMap, ListBuffer}
import scala.tools.nsc.util.{FreshNameCreator, TreeSet}
/** Translate expressions of the form reflect.Code.lift(exp)
* to the lifted "reflect trees" representation of exp.
*
* @author Gilles Dubochet
* @version 1.0
*/
abstract class LiftCode extends Transform {
import global._ // the global environment
import definitions._ // standard classes and methods
import typer.{typed, atOwner} // methods to type trees
import posAssigner.atPos // for filling in tree positions
/** the following two members override abstract members in Transform */
val phaseName: String = "liftcode"
def newTransformer(unit: CompilationUnit): Transformer =
new AddRefFields(unit)
class AddRefFields(unit: CompilationUnit) extends Transformer {
override def transform(tree: Tree): Tree = tree match {
case Apply(lift, List(tree))
if lift.symbol == Code_lift =>
typed(atPos(tree.pos)(codify(tree)))
case _ =>
super.transform(tree)
}
}
case class FreeValue(tree: Tree) extends reflect.Tree
class ReifyEnvironment extends HashMap[Symbol, reflect.Symbol] {
var targets = new HashMap[String, Option[reflect.LabelSymbol]]()
def addTarget(name: String, target: reflect.LabelSymbol): Unit =
targets.update(name, Some(target))
def getTarget(name: String): Option[reflect.LabelSymbol] =
targets.get(name) match {
case None =>
targets.update(name, None)
None
//case Some(None) => None //bq:redundant
case Some(tgt) => tgt
}
def hasAllTargets: Boolean =
targets.elements.map(_._2).forall {
case Some(_) => true
case None => false
}
override def update(sym: Symbol, rsym: reflect.Symbol) =
super.update(sym,rsym)
}
class Reifier(env: ReifyEnvironment, currentOwner: reflect.Symbol)
extends SymbolReifier
{
val symbols: global.type = global
def reify(tree: Tree): reflect.Tree = tree match {
case Ident(_) =>
val rsym = reify(tree.symbol);
//Console.println("LiftCode: seen ident")
if (rsym == reflect.NoSymbol) {
//Console.println(" free = "+tree)
FreeValue(tree)
} else {
//Console.println(" rsym = "+rsym)
reflect.Ident(rsym)
}
case Select(qual, _) =>
val rsym = reify(tree.symbol);
if (rsym == reflect.NoSymbol) throw new TypeError("cannot reify symbol: " + tree.symbol)
else reflect.Select(reify(qual), reify(tree.symbol))
case _ : StubTree => reflect.Literal(0)
case Literal(constant) =>
reflect.Literal(constant.value)
case Apply(name, args) if name.toString().startsWith("label$") =>
env.getTarget(name.toString()) match {
case None => throw new TypeError("cannot reify tree (no forward jumps allowed): " + tree)
case Some(label) => reflect.Goto(label)
}
case Apply(fun, args) =>
reflect.Apply(reify(fun), args map reify)
case TypeApply(fun, args) =>
reflect.TypeApply(reify(fun), args map (_.tpe) map reify)
case Function(vparams, body) =>
var env1 = env
for (vparam <- vparams) {
val local = reflect.LocalValue(
currentOwner, vparam.symbol.name.toString(), reify(vparam.symbol.tpe));
env1.update(vparam.symbol, local);
}
reflect.Function(vparams map (_.symbol) map env1,
new Reifier(env1, currentOwner).reify(body))
case tree@This(_) if tree.symbol.isModule =>
// there is no reflect node for a module's this, so
// represent it as a selection of the module
reify(typed(
Select(This(tree.symbol.owner), tree.symbol.name)))
case This(_) =>
reflect.This(reify(tree.symbol))
case Block(stats, expr) =>
reflect.Block(stats.map(reify), reify(expr))
case New(clazz) =>
val reifiedClass = reify(clazz)
reflect.New(reifiedClass)
case Typed(t, _) =>
reify(t)
case If(cond, thenp, elsep) =>
reflect.If(reify(cond), reify(thenp), reify(elsep))
case Assign(lhs, rhs) =>
reflect.Assign(reify(lhs), reify(rhs))
case LabelDef(name, Nil, body) =>
val sym = new reflect.LabelSymbol(name.toString())
env.addTarget(name.toString(), sym)
val res = reflect.Target(sym, reify(body))
res
case vd @ ValDef(mods, name, tpt, rhs) =>
val rtpe = reify(vd.tpe) // will return null, currently?!
val sym = reflect.LocalValue(currentOwner, name.toString(), rtpe)
env(vd.symbol) = sym // bq: despite Scala's scoping rules, this should work because references to vd.symbol were type checked.
val rhs_ = reify(rhs)
reflect.ValDef(sym, rhs_)
case cd @ ClassDef(mods, name, tparams, impl) =>
if(!tparams.isEmpty)
throw new TypeError("cannot handle polymorphic ClassDef ("+name+"): " + tparams)
val rsym = reify(cd.symbol)
val rimp = reify(impl)
val rtpe = reify(impl.self.tpt.tpe) //todo: update
reflect.ClassDef(rsym, rtpe, rimp.asInstanceOf[reflect.Template])
case tmpl @ Template(parents, self, body) =>
val rparents = for (p <- parents) yield { reify(p.tpe) }
//todo: add self to reified templates
reflect.Template(rparents, body.map(reify))
case dd @ DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
if(!tparams.isEmpty)
throw new TypeError("cannot handle polymorphic DefDef ("+name+"): " + tparams)
val rsym = reify(dd.symbol)
val rparss = vparamss map { x => x map (reify) }
val rret = reify(tpt.tpe)
val rrhs = reify(rhs)
reflect.DefDef(rsym, rparss, rret, rrhs)
case sp @ Super(qual: Name, mix: Name) =>
val rsym = reify(sp.symbol)
reflect.Super(rsym)
case _ =>
throw new TypeError("cannot reify tree ("+tree.getClass()+"): " + tree)
}
override def reify(sym: Symbol): reflect.Symbol =
env.get(sym) match {
case Some(rsym) =>
rsym
case None =>
super.reify(sym)
}
}
type InjectEnvironment = ListMap[reflect.Symbol, Name]
class Injector(env: InjectEnvironment, fresh: FreshNameCreator) {
// todo replace className by caseName in CaseClass once we have switched to nsc.
def className(value: AnyRef): String = value match {
case _ :: _ => "scala.$colon$colon"
case reflect.MethodType(_, _) =>
if (value.isInstanceOf[reflect.ImplicitMethodType])
"scala.reflect.ImplicitMethodType"
else
"scala.reflect.MethodType"
case x:Product =>
"scala.reflect."+x.productPrefix //caseName
//case _ => // bq:unreachable code
// ""
}
def objectName(value: Any): String = value match {
case Nil => "scala.Nil"
case reflect.NoSymbol => "scala.reflect.NoSymbol"
case reflect.RootSymbol => "scala.reflect.RootSymbol"
case reflect.NoPrefix => "scala.reflect.NoPrefix"
case reflect.NoType => "scala.reflect.NoType"
case _ => ""
}
def inject(value: Any): Tree = {
def treatProduct(c: Product) = {
val name = objectName(c)
if (name.length() != 0)
gen.mkAttributedRef(definitions.getModule(name))
else {
val name = className(c)
if (name.length() == 0) throw new Error("don't know how to inject " + value)
val injectedArgs = new ListBuffer[Tree]
for (i <- 0 until c.productArity)
injectedArgs += inject(c.productElement(i))
New(Ident(definitions.getClass(name)), List(injectedArgs.toList))
}
}
value match {
case FreeValue(tree) =>
New(Ident(definitions.getClass("scala.reflect.Literal")), List(List(tree)))
case () => Literal(Constant(()))
case x: String => Literal(Constant(x))
case x: Boolean => Literal(Constant(x))
case x: Byte => Literal(Constant(x))
case x: Short => Literal(Constant(x))
case x: Char => Literal(Constant(x))
case x: Int => Literal(Constant(x))
case x: Long => Literal(Constant(x))
case x: Float => Literal(Constant(x))
case x: Double => Literal(Constant(x))
case c: Product => treatProduct(c)
case null =>
gen.mkAttributedRef(definitions.getModule("scala.reflect.NoType"))
case _ =>
throw new Error("don't know how to inject " + value)
}
}
} // Injector
def reify(tree: Tree): reflect.Tree =
new Reifier(new ReifyEnvironment(), reflect.NoSymbol).reify(tree)
def inject(code: reflect.Tree): Tree =
new Injector(ListMap.empty, new FreshNameCreator.Default).inject(code)
def codify (tree: Tree): Tree =
New(TypeTree(appliedType(definitions.CodeClass.typeConstructor,
List(tree.tpe))),
List(List(inject(reify(tree)))))
}
// case EmptyTree =>
// case LiftPoint(tree) =>
// case PackageDef(name, stats) =>
// case ClassDef(mods, name, tparams, impl) =>
// case ValDef(mods, name, tpt, rhs) =>
// case DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
// case TypeDef(mods, name, tparams, rhs) =>
// case LabelDef(name, params, rhs) =>
// case Template(parents, self, body) =>
// case Block(stats, expr) =>
// case ArrayValue(elemtpt, trees) =>
// case Assign(lhs, rhs) =>
// case If(cond, thenp, elsep) =>
// case Match(selector, cases) =>
// case Return(expr) =>
// case Try(block, catches, finalizer) =>
// case Throw(expr) =>
// case New(tpt) =>
// case Typed(expr, tpt) =>
// case TypeApply(fun, args) =>
// case Apply(fun, args) =>
// case Super(qual, mix) =>
// case This(qual) =>
// case Select(qualifier, selector) =>
// case Ident(name) =>
// case Literal(value) =>
// case TypeTree() =>
// /* Pattern matching */
// case CaseDef(pat, guard, body) =>
// case Sequence(trees) =>
// case Alternative(trees) =>
// case Star(elem) =>
// case Bind(name, body) =>
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