clazz an inner class? */
private def isInner(clazz: Symbol) =
!clazz.isPackageClass && !clazz.outerClass.isStaticOwner
/** Does given clazz define an outer field? */
def hasOuterField(clazz: Symbol) = {
def hasSameOuter(parent: Type) =
parent.typeSymbol.isClass &&
clazz.owner.isClass &&
clazz.owner == parent.typeSymbol.owner &&
parent.prefix =:= clazz.owner.thisType
isInner(clazz) && !clazz.isTrait &&
(clazz.info.parents.isEmpty || !hasSameOuter(clazz.info.parents.head))
}
private def outerField(clazz: Symbol): Symbol = {
val result = clazz.info.member(nme getterToLocal nme.OUTER)
assert(result != NoSymbol, "no outer field in "+clazz+clazz.info.decls+" at "+phase)
result
}
def outerAccessor(clazz: Symbol): Symbol = {
val firstTry = clazz.info.decl(clazz expandedName nme.OUTER)
if (firstTry != NoSymbol && firstTry.outerSource == clazz) firstTry
else clazz.info.decls find (_.outerSource == clazz) getOrElse NoSymbol
}
/** * The type transformation method: *
*$outer field to an inner class which is
* not a trait.
*
* Add an outer accessor $outer$$C to every inner class
* with fully qualified name C that is not an interface.
* The outer accesssor is abstract for traits, concrete for other
* classes.
*
* 3a. Also add overriding accessor defs to every class that inherits * mixin classes with outer accessor defs (unless the superclass * already inherits the same mixin). *
*outerParam
* values for outer parameters of constructors.
* The class provides methods for referencing via outer.
*/
abstract class OuterPathTransformer(unit: CompilationUnit) extends TypingTransformer(unit) {
/** The directly enclosing outer parameter, if we are in a constructor */
protected var outerParam: Symbol = NoSymbol
/** The first outer selection from currently transformed tree.
* The result is typed but not positioned.
*/
protected def outerValue: Tree =
if (outerParam != NoSymbol) ID(outerParam)
else outerSelect(THIS(currentClass))
/** Select and apply outer accessor from 'base'
* The result is typed but not positioned.
* If the outer access is from current class and current class is final
* take outer field instead of accessor
*/
private def outerSelect(base: Tree): Tree = {
val outerAcc = outerAccessor(base.tpe.typeSymbol.toInterface)
val currentClass = this.currentClass //todo: !!! if this line is removed, we get a build failure that protected$currentClass need an override modifier
// outerFld is the $outer field of the current class, if the reference can
// use it (i.e. reference is allowed to be of the form this.$outer),
// otherwise it is NoSymbol
val outerFld =
if (outerAcc.owner == currentClass &&
base.tpe =:= currentClass.thisType &&
outerAcc.owner.isFinal)
outerField(currentClass) suchThat (_.owner == currentClass)
else
NoSymbol
val path =
if (outerFld != NoSymbol) Select(base, outerFld)
else Apply(Select(base, outerAcc), Nil)
localTyper typed path
}
/** The path
* * which refers to the outer instance of class`base'.$outer$$C1 ... .$outer$$Cn
to of
* value base. The result is typed but not positioned.
*
* @param base ...
* @param from ...
* @param to ...
* @return ...
*/
protected def outerPath(base: Tree, from: Symbol, to: Symbol): Tree = {
//Console.println("outerPath from "+from+" to "+to+" at "+base+":"+base.tpe)
//assert(base.tpe.widen.baseType(from.toInterface) != NoType, ""+base.tpe.widen+" "+from.toInterface)//DEBUG
if (from == to || from.isImplClass && from.toInterface == to) base
else outerPath(outerSelect(base), from.outerClass, to)
}
override def transform(tree: Tree): Tree = {
val savedOuterParam = outerParam
try {
tree match {
case Template(_, _, _) =>
outerParam = NoSymbol
case DefDef(_, _, _, vparamss, _, _) =>
if (tree.symbol.isClassConstructor && isInner(tree.symbol.owner)) {
outerParam = vparamss.head.head.symbol
assert(outerParam.name startsWith nme.OUTER, outerParam.name)
}
case _ =>
}
super.transform(tree)
}
finally {
outerParam = savedOuterParam
}
}
}
/** * The phase performs the following transformations on terms: *
** An class which is not an interface and is not static gets an outer * accessor (@see outerDefs). *
** 1a. A class which is not a trait gets an outer field. *
*C.this where C refers to an
* outer class is replaced by a selection
* this.$outer$$C1 ... .$outer$$Cn (@see outerPath)
* Q.<init>(OUTER, args) where OUTER
* is the qualifier corresponding to the singleton type Q.
* this.<init>(args) in a
* secondary constructor is augmented to this.<init>(OUTER, args)
* where OUTER is the last parameter of the secondary constructor.
* private modifier from class members M
* that are accessed from an inner class.
* protected modifier from class members M
* that are accessed without a super qualifier accessed from an inner
* class or trait.
* private and protected modifiers
* from type symbols
* private modifiers from members of traits
*
* Note: The whole transform is run in phase explicitOuter.next.
*
mixinClass.
*
* @param mixinClass The mixin class which defines the abstract outer
* accessor which is implemented by the generated one.
* @pre mixinClass is an inner class
*/
def mixinOuterAccessorDef(mixinClass: Symbol): Tree = {
val outerAcc = outerAccessor(mixinClass) overridingSymbol currentClass
assert(outerAcc != NoSymbol)
val path =
if (mixinClass.owner.isTerm) THIS(mixinClass.owner.enclClass)
else gen.mkAttributedQualifier(currentClass.thisType baseType mixinClass prefix)
val rhs = ExplicitOuterTransformer.this.transform(path)
// @S: atPos not good enough because of nested atPos in DefDef method, which gives position from wrong class!
rhs setPos currentClass.pos
typedPos(currentClass.pos) { (DEF(outerAcc) === rhs) setPos currentClass.pos }
}
/** If FLAG is set on symbol, sets notFLAG (this exists in anticipation of generalizing). */
def setNotFlags(sym: Symbol, flags: Int*) {
val notMap = Map(
PRIVATE -> notPRIVATE,
PROTECTED -> notPROTECTED
)
for (f <- flags ; notFlag <- notMap get f ; if sym hasFlag f)
sym setFlag notFlag
}
def matchTranslation(tree: Match) = {
val Match(selector, cases) = tree
var nselector = transform(selector)
def makeGuardDef(vs: List[Symbol], guard: Tree) = {
val gdname = newName(guard.pos, "gd")
val method = currentOwner.newMethod(tree.pos, gdname) setFlag SYNTHETIC
val fmls = vs map (_.tpe)
val tpe = new MethodType(method newSyntheticValueParams fmls, BooleanClass.tpe)
method setInfo tpe
localTyper typed (DEF(method) === {
new ChangeOwnerTraverser(currentOwner, method) traverse guard
new TreeSymSubstituter(vs, method.paramss.head) traverse guard
guard
})
}
val nguard = new ListBuffer[Tree]
val ncases =
for (CaseDef(p, guard, b) <- cases) yield {
val gdcall =
if (guard == EmptyTree) EmptyTree
else {
val vs = Pattern(p).deepBoundVariables
val guardDef = makeGuardDef(vs, guard)
nguard += transform(guardDef) // building up list of guards
localTyper typed (Ident(guardDef.symbol) APPLY (vs map Ident))
}
(CASE(transform(p)) IF gdcall) ==> transform(b)
}
def isUncheckedAnnotation(tpe: Type) = tpe hasAnnotation UncheckedClass
def isSwitchAnnotation(tpe: Type) = tpe hasAnnotation SwitchClass
val (checkExhaustive, requireSwitch) = nselector match {
case Typed(nselector1, tpt) =>
val unchecked = isUncheckedAnnotation(tpt.tpe)
if (unchecked)
nselector = nselector1
(!unchecked, isSwitchAnnotation(tpt.tpe))
case _ =>
(true, false)
}
val t = atPos(tree.pos) {
val context = MatrixContext(transform, localTyper, currentOwner, tree.tpe)
val t_untyped = handlePattern(nselector, ncases, checkExhaustive, context)
/* if @switch annotation is present, verify the resulting tree is a Match */
if (requireSwitch) t_untyped match {
case Block(_, Match(_, _)) => // ok
case _ =>
unit.error(tree.pos, "could not emit switch for @switch annotated match")
}
localTyper.typed(t_untyped, context.matchResultType)
}
if (nguard.isEmpty) t
else Block(nguard.toList, t) setType t.tpe
}
/** The main transformation method */
override def transform(tree: Tree): Tree = {
val sym = tree.symbol
if (sym != null && sym.isType) //(9)
setNotFlags(sym, PRIVATE, PROTECTED)
tree match {
case Template(parents, self, decls) =>
val newDefs = new ListBuffer[Tree]
atOwner(tree, currentOwner) {
if (!(currentClass hasFlag INTERFACE) || (currentClass hasFlag lateINTERFACE)) {
if (isInner(currentClass)) {
if (hasOuterField(currentClass))
newDefs += outerFieldDef // (1a)
newDefs += outerAccessorDef // (1)
}
if (!currentClass.isTrait)
for (mc <- currentClass.mixinClasses)
if (outerAccessor(mc) != NoSymbol)
newDefs += mixinOuterAccessorDef(mc)
}
}
super.transform(
treeCopy.Template(tree, parents, self,
if (newDefs.isEmpty) decls else decls ::: newDefs.toList)
)
case DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
if (sym.isClassConstructor) {
rhs match {
case Literal(_) =>
Predef.error("unexpected case") //todo: remove
case _ =>
val clazz = sym.owner
val vparamss1 =
if (isInner(clazz)) { // (4)
val outerParam =
sym.newValueParameter(sym.pos, nme.OUTER) setInfo outerField(clazz).info
((ValDef(outerParam) setType NoType) :: vparamss.head) :: vparamss.tail
} else vparamss
super.transform(treeCopy.DefDef(tree, mods, name, tparams, vparamss1, tpt, rhs))
}
} else
super.transform(tree)
case This(qual) =>
if (sym == currentClass || (sym hasFlag MODULE) && sym.isStatic) tree
else atPos(tree.pos)(outerPath(outerValue, currentClass.outerClass, sym)) // (5)
case Select(qual, name) =>
if (currentClass != sym.owner/* && currentClass != sym.moduleClass*/) // (3)
sym.makeNotPrivate(sym.owner)
val qsym = qual.tpe.widen.typeSymbol
if ((sym hasFlag PROTECTED) && //(4)
(qsym.isTrait || !(qual.isInstanceOf[Super] || (qsym isSubClass currentClass))))
sym setFlag notPROTECTED
super.transform(tree)
case Apply(sel @ Select(qual, name), args) if (name == nme.CONSTRUCTOR && isInner(sel.symbol.owner)) =>
val outerVal = atPos(tree.pos)(qual match {
// it's a call between constructors of same class
case _: This =>
assert(outerParam != NoSymbol)
outerValue
case _ =>
gen.mkAttributedQualifier(qual.tpe.prefix match {
case NoPrefix => sym.owner.outerClass.thisType
case x => x
})
})
super.transform(treeCopy.Apply(tree, sel, outerVal :: args))
// TransMatch hook
case mch: Match =>
matchTranslation(mch)
case _ =>
val x = super.transform(tree)
if (x.tpe eq null) x
else x setType transformInfo(currentOwner, x.tpe)
}
}
/** The transformation method for whole compilation units */
override def transformUnit(unit: CompilationUnit) {
cunit = unit
atPhase(phase.next) { super.transformUnit(unit) }
cunit = null
}
}
override def newPhase(prev: scala.tools.nsc.Phase): StdPhase =
new Phase(prev)
class Phase(prev: scala.tools.nsc.Phase) extends super.Phase(prev) {
override val checkable = false
}
}