diff options
Diffstat (limited to 'src/compiler')
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/Erasure.scala | 14 | ||||
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/UnCurry.scala | 118 |
2 files changed, 80 insertions, 52 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index a04625c9c5..a7cf6d9e8d 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -336,7 +336,18 @@ abstract class Erasure extends AddInterfaces case MethodType(params, restpe) => val buf = new StringBuffer("(") - params foreach (p => buf append jsig(p.tpe)) + params foreach (p => { + val tp = p.attachments.get[TypeParamVarargsAttachment] match { + case Some(att) => + // For @varargs forwarders, a T* parameter has type Array[Object] in the forwarder + // instead of Array[T], as the latter would erase to Object (instead of Array[Object]). + // To make the generic signature correct ("[T", not "[Object"), an attachment on the + // parameter symbol stores the type T that was replaced by Object. + buf.append("["); att.typeParamRef + case _ => p.tpe + } + buf append jsig(tp) + }) buf append ")" buf append (if (restpe.typeSymbol == UnitClass || sym0.isConstructor) VOID_TAG.toString else jsig(restpe)) buf.toString @@ -1178,4 +1189,5 @@ abstract class Erasure extends AddInterfaces } private class TypeRefAttachment(val tpe: TypeRef) + class TypeParamVarargsAttachment(val typeParamRef: Type) } diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala index 870c35338c..17f4471533 100644 --- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala +++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala @@ -763,72 +763,88 @@ abstract class UnCurry extends InfoTransform if (!dd.symbol.hasAnnotation(VarargsClass) || !enteringUncurry(mexists(dd.symbol.paramss)(sym => definitions.isRepeatedParamType(sym.tpe)))) return flatdd - def toArrayType(tp: Type): Type = { - val arg = elementType(SeqClass, tp) - // to prevent generation of an `Object` parameter from `Array[T]` parameter later - // as this would crash the Java compiler which expects an `Object[]` array for varargs - // e.g. def foo[T](a: Int, b: T*) - // becomes def foo[T](a: Int, b: Array[Object]) - // instead of def foo[T](a: Int, b: Array[T]) ===> def foo[T](a: Int, b: Object) - arrayType( - if (arg.typeSymbol.isTypeParameterOrSkolem) ObjectTpe - else arg - ) - } + val forwSym = currentClass.newMethod(dd.name.toTermName, dd.pos, VARARGS | SYNTHETIC | flatdd.symbol.flags) - val theTyper = typer.atOwner(dd, currentClass) - val flatparams = flatdd.symbol.paramss.head val isRepeated = enteringUncurry(dd.symbol.info.paramss.flatten.map(sym => definitions.isRepeatedParamType(sym.tpe))) - // create the type - val forwformals = map2(flatparams, isRepeated) { - case (p, true) => toArrayType(p.tpe) - case (p, false)=> p.tpe - } - val forwresult = dd.symbol.tpe_*.finalResultType - val forwformsyms = map2(forwformals, flatparams)((tp, oldparam) => - currentClass.newValueParameter(oldparam.name.toTermName, oldparam.pos).setInfo(tp) - ) - def mono = MethodType(forwformsyms, forwresult) - val forwtype = dd.symbol.tpe match { - case MethodType(_, _) => mono - case PolyType(tps, _) => PolyType(tps, mono) - } + val oldPs = flatdd.symbol.paramss.head + + // see comment in method toArrayType below + val arrayTypesMappedToObject = mutable.Map.empty[Symbol, Type] - // create the symbol - val forwsym = currentClass.newMethod(dd.name.toTermName, dd.pos, VARARGS | SYNTHETIC | flatdd.symbol.flags) setInfo forwtype - def forwParams = forwsym.info.paramss.flatten - - // create the tree - val forwtree = theTyper.typedPos(dd.pos) { - val locals = map3(forwParams, flatparams, isRepeated) { - case (_, fp, false) => null - case (argsym, fp, true) => - Block(Nil, - gen.mkCast( - gen.mkWrapArray(Ident(argsym), elementType(ArrayClass, argsym.tpe)), - seqType(elementType(SeqClass, fp.tpe)) - ) - ) + val forwTpe = { + val (oldTps, tps) = dd.symbol.tpe match { + case PolyType(oldTps, _) => + val newTps = oldTps.map(_.cloneSymbol(forwSym)) + (oldTps, newTps) + + case _ => (Nil, Nil) } - val seqargs = map2(locals, forwParams) { - case (null, argsym) => Ident(argsym) - case (l, _) => l + + def toArrayType(tp: Type, newParam: Symbol): Type = { + val arg = elementType(SeqClass, tp) + val elem = if (arg.typeSymbol.isTypeParameterOrSkolem && !(arg <:< AnyRefTpe)) { + // To prevent generation of an `Object` parameter from `Array[T]` parameter later + // as this would crash the Java compiler which expects an `Object[]` array for varargs + // e.g. def foo[T](a: Int, b: T*) + // becomes def foo[T](a: Int, b: Array[Object]) + // instead of def foo[T](a: Int, b: Array[T]) ===> def foo[T](a: Int, b: Object) + // + // In order for the forwarder method to type check we need to insert a cast: + // def foo'[T'](a: Int, b: Array[Object]) = foo[T'](a, wrapRefArray(b).asInstanceOf[Seq[T']]) + // The target element type for that cast (T') is stored in the `arrayTypesMappedToObject` map. + val originalArg = arg.substSym(oldTps, tps) + arrayTypesMappedToObject(newParam) = originalArg + // Store the type parameter that was replaced by Object to emit the correct generic signature + newParam.updateAttachment(new erasure.TypeParamVarargsAttachment(originalArg)) + ObjectTpe + } else + arg + arrayType(elem) } - val end = if (forwsym.isConstructor) List(UNIT) else Nil - DefDef(forwsym, BLOCK(Apply(gen.mkAttributedRef(flatdd.symbol), seqargs) :: end : _*)) + val ps = map2(oldPs, isRepeated)((oldParam, isRep) => { + val newParam = oldParam.cloneSymbol(forwSym) + val tp = if (isRep) toArrayType(oldParam.tpe, newParam) else oldParam.tpe + newParam.setInfo(tp) + }) + + val resTp = dd.symbol.tpe_*.finalResultType.substSym(oldPs, ps) + val mt = MethodType(ps, resTp) + val r = if (tps.isEmpty) mt else PolyType(tps, mt) + r.substSym(oldTps, tps) + } + + forwSym.setInfo(forwTpe) + val newPs = forwTpe.params + + val theTyper = typer.atOwner(dd, currentClass) + val forwTree = theTyper.typedPos(dd.pos) { + val seqArgs = map3(newPs, oldPs, isRepeated)((param, oldParam, isRep) => { + if (!isRep) Ident(param) + else { + val parTp = elementType(ArrayClass, param.tpe) + val wrap = gen.mkWrapArray(Ident(param), parTp) + arrayTypesMappedToObject.get(param) match { + case Some(tp) => gen.mkCast(wrap, seqType(tp)) + case _ => wrap + } + } + }) + + val forwCall = Apply(gen.mkAttributedRef(flatdd.symbol), seqArgs) + DefDef(forwSym, if (forwSym.isConstructor) Block(List(forwCall), UNIT) else forwCall) } // check if the method with that name and those arguments already exists in the template - currentClass.info.member(forwsym.name).alternatives.find(s => s != forwsym && s.tpe.matches(forwsym.tpe)) match { + currentClass.info.member(forwSym.name).alternatives.find(s => s != forwSym && s.tpe.matches(forwSym.tpe)) match { case Some(s) => reporter.error(dd.symbol.pos, "A method with a varargs annotation produces a forwarder method with the same signature " + s.tpe + " as an existing method.") case None => // enter symbol into scope - currentClass.info.decls enter forwsym - addNewMember(forwtree) + currentClass.info.decls enter forwSym + addNewMember(forwTree) } flatdd |