package dotty.tools.dotc
package transform
import core._
import Symbols._, Types._, Contexts._, SymDenotations._, DenotTransformers._, Flags._
import util.Positions._
import SymUtils._
import StdNames._, NameOps._
class MixinOps(cls: ClassSymbol, thisTransform: DenotTransformer)(implicit ctx: Context) {
import ast.tpd._
val superCls: Symbol = cls.superClass
val mixins: List[ClassSymbol] = cls.mixins
def implementation(member: TermSymbol): TermSymbol = {
val res = member.copy(
owner = cls,
name = member.name.stripScala2LocalSuffix,
flags = member.flags &~ Deferred,
info = cls.thisType.memberInfo(member)).enteredAfter(thisTransform).asTerm
res.addAnnotations(member.annotations)
res
}
def superRef(target: Symbol, pos: Position = cls.pos): Tree = {
val sup = if (target.isConstructor && !target.owner.is(Trait))
Super(This(cls), tpnme.EMPTY, true)
else
Super(This(cls), target.owner.name.asTypeName, false, target.owner)
//println(i"super ref $target on $sup")
ast.untpd.Select(sup.withPos(pos), target.name)
.withType(NamedType.withFixedSym(sup.tpe, target))
//sup.select(target)
}
/** Is `sym` a member of implementing class `cls`?
* The test is performed at phase `thisTransform`.
*/
def isCurrent(sym: Symbol) =
ctx.atPhase(thisTransform) { implicit ctx =>
cls.info.member(sym.name).hasAltWith(_.symbol == sym)
}
/** Does `method` need a forwarder to in class `cls`
* Method needs a forwarder in those cases:
* - there's a class defining a method with same signature
* - there are multiple traits defining method with same signature
*/
def needsForwarder(meth: Symbol): Boolean = {
lazy val competingMethods = cls.baseClasses.iterator
.filter(_ ne meth.owner)
.map(meth.overriddenSymbol)
.filter(_.exists)
.toList
def needsDisambiguation = competingMethods.exists(x=> !(x is Deferred)) // multiple implementations are available
def hasNonInterfaceDefinition = competingMethods.exists(!_.owner.is(Trait)) // there is a definition originating from class
meth.is(Method, butNot = PrivateOrAccessorOrDeferred) &&
isCurrent(meth) &&
(needsDisambiguation || hasNonInterfaceDefinition || meth.owner.is(Scala2x))
}
final val PrivateOrAccessorOrDeferred = Private | Accessor | Deferred
def forwarder(target: Symbol) = (targs: List[Type]) => (vrefss: List[List[Tree]]) =>
superRef(target).appliedToTypes(targs).appliedToArgss(vrefss)
}