/* NSC -- new Scala compiler
* Copyright 2005-2006 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc.transform
import symtab._
import Flags._
import scala.collection.mutable.ListBuffer
import scala.tools.nsc.util.{Position,NoPosition}
abstract class Mixin extends InfoTransform {
import global._
import definitions._
import posAssigner.atPos
/** The name of the phase: */
val phaseName: String = "mixin"
/** The phase might set the fiollowing new flags: */
override def phaseNewFlags: long = lateMODULE | notABSTRACT
/** This map contains a binding (class -> info) if
* the class with this info at phase mixinPhase has been treated for mixin composition
*/
private val treatedClassInfos = collection.mutable.Map[Symbol, Type]()
// --------- helper functions -----------------------------------------------
/** A member of a trait is implemented statically if its implementation after the
* mixin transform is in the static implementation module. To be statically
* implemented, a member must be a method that belonged to the trait's implementation class
* before (e.g. it is not abstract). Not statically implemented are
* - non-private modules: these are implemented directly in the mixin composition class
* (private modules, on the other hand, are implemented statically, but their
* module variable is not. all such private modules are lifted, because
* non-lifted private modules have been eliminated in ExplicitOuter)
* - field accessors and superaccessors
*/
private def isImplementedStatically(sym: Symbol) =
sym.owner.isImplClass && sym.isMethod &&
(!sym.isModule || sym.hasFlag(PRIVATE | LIFTED)) &&
!(sym hasFlag (ACCESSOR | SUPERACCESSOR))
/** A member of a trait is static only if it belongs only to the
* implementation class, not the interface, and it is implemented
* statically.
*/
private def isStaticOnly(sym: Symbol) =
isImplementedStatically(sym) && sym.isImplOnly
/** A member of a trait is forwarded if it is implemented statically and it
* is also visible in the trait's interface. In that case, a forwarder to
* the member's static implementation will be added to the class that
* inherits the trait.
*/
private def isForwarded(sym: Symbol) =
isImplementedStatically(sym) && !sym.isImplOnly && !sym.isCaseFactory
/** Maps the type of an implementation class to its interface;
* maps all other types to themselves.
*/
private def toInterface(tp: Type): Type =
atPhase(currentRun.mixinPhase)(tp.symbol.toInterface).tpe
/** Maps all parts of this type that refer to implementation classes to
* their corresponding interfaces.
*/
private val toInterfaceMap = new TypeMap {
def apply(tp: Type): Type = mapOver( tp match {
case TypeRef(pre, sym, args) if (sym.isImplClass) =>
typeRef(pre, atPhase(currentRun.mixinPhase)(sym.toInterface), args)
case _ => tp
})
}
/** The implementation class corresponding to a currently compiled interface.
* todo: try to use Symbol.implClass instead?
*/
private def implClass(iface: Symbol): Symbol = {
val impl = iface.implClass
if (impl != NoSymbol) impl else erasure.implClass(iface)
}
/** Returns the symbol that is accessed by a super-accessor in a mixin composition.
*
* @param base The class in mwhich everything is mixed together
* @param member The symbol statically referred to by the superaccessor in the trait
* @param mixinClass The mixin class that produced the superaccessor
*/
private def rebindSuper(base: Symbol, member: Symbol, mixinClass: Symbol): Symbol =
atPhase(currentRun.refchecksPhase) {
var bcs = base.info.baseClasses.dropWhile(mixinClass !=).tail
var sym: Symbol = NoSymbol
if (settings.debug.value)
log("starting rebindsuper " + base + " " + member + ":" + member.tpe +
" " + mixinClass + " " + base.info.baseClasses)
while (!bcs.isEmpty && sym == NoSymbol) {
if (settings.debug.value) {
val other = bcs.head.info.nonPrivateDecl(member.name);
log("rebindsuper " + bcs.head + " " + other + " " + other.tpe +
" " + other.hasFlag(DEFERRED))
}
sym = member.overridingSymbol(bcs.head).suchThat(sym => !sym.hasFlag(DEFERRED | BRIDGE))
bcs = bcs.tail
}
assert(sym != NoSymbol, member)
sym
}
// --------- type transformation -----------------------------------------------
/** Add given member to given class, and mark member as mixed-in.
*/
def addMember(clazz: Symbol, member: Symbol): Symbol = {
if (settings.debug.value) log("new member of " + clazz + ":" + member.defString)
clazz.info.decls enter member
member setFlag MIXEDIN
}
/** Add getters and setters for all non-module fields of an implementation
* class to its interface unless they are already present. This is done
* only once per class. The mixedin flag is used to remember whether late
* members have been added to an interface.
*
* @param clazz ...
*/
def addLateInterfaceMembers(clazz: Symbol): unit =
if ((treatedClassInfos get clazz) != Some(clazz.info)) {
treatedClassInfos(clazz) = clazz.info
assert(phase == currentRun.mixinPhase)
/** Create a new getter. Getters are never private or local. They are
* always accessors and deferred. */
def newGetter(field: Symbol): Symbol =
clazz.newMethod(field.pos, nme.getterName(field.name))
.setFlag(field.flags & ~(PRIVATE | LOCAL) | ACCESSOR | lateDEFERRED)
.setInfo(MethodType(List(), field.info))
/** Create a new setter. Setters are never private or local. They are
* always accessors and deferred. */
def newSetter(field: Symbol): Symbol =
clazz.newMethod(field.pos, nme.getterToSetter(nme.getterName(field.name)))
.setFlag(field.flags & ~(PRIVATE | LOCAL) | ACCESSOR | lateDEFERRED)
.setInfo(MethodType(List(field.info), UnitClass.tpe))
clazz.info // make sure info is up to date, so that implClass is set.
val impl = implClass(clazz)
assert(impl != NoSymbol)
for (val member <- impl.info.decls.toList) {
if (!member.isMethod && !member.isModule && !member.isModuleVar) {
assert(member.isTerm && !member.hasFlag(DEFERRED), member)
if (member.getter(impl) hasFlag PRIVATE) {
member.makeNotPrivate(clazz) // this will also make getter&setter not private
}
val getter = member.getter(clazz)
if (getter == NoSymbol) addMember(clazz, newGetter(member))
if (!member.tpe.isInstanceOf[ConstantType]) {
val setter = member.setter(clazz)
if (setter == NoSymbol) addMember(clazz, newSetter(member))
}
}
}
if (settings.debug.value) log("new defs of " + clazz + " = " + clazz.info.decls);
}
/** Add all members to be mixed in into a (non-trait-) class
* These are:
* for every mixin trait T that is not also inherited by the superclass:
* add late interface members to T and then:
* - if a member M of T is forwarded to the implementation class, add
* a forwarder for M unless one exists already.
* The alias of the forwarder is the static member it forwards to.
* - for every abstract accessor in T, add a field and an implementation for that acessor
* - for every super accessor in T, add an implementation of that accessor
* - for every module in T, add a module
*/
def addMixedinMembers(clazz: Symbol): unit = {
if (!(clazz hasFlag JAVA) && (treatedClassInfos get clazz) != Some(clazz.info)) {
treatedClassInfos(clazz) = clazz.info
assert(!clazz.isTrait, clazz)
assert(!clazz.info.parents.isEmpty, clazz)
// first complete the superclass with mixed in members
addMixedinMembers(clazz.superClass)
//Console.println("adding members of " + clazz.info.baseClasses.tail.takeWhile(superclazz !=) + " to " + clazz);//DEBUG
/** Mix in members of implementation class mixinClass into class clazz */
def mixinImplClassMembers(impl: Symbol, iface: Symbol): unit = {
assert (impl.isImplClass)
for (val member <- impl.info.decls.toList) {
if (isForwarded(member)) {
val imember = member.overriddenSymbol(iface)
//Console.println("mixin member "+member+":"+member.tpe+member.locationString+" "+imember+" "+imember.overridingSymbol(clazz)+" to "+clazz+" with scope "+clazz.info.decls)//DEBUG
if (imember.overridingSymbol(clazz) == NoSymbol &&
clazz.info.findMember(member.name, 0, lateDEFERRED, false).alternatives.contains(imember)) {
val member1 = addMember(
clazz,
member.cloneSymbol(clazz) setPos clazz.pos resetFlag (DEFERRED | lateDEFERRED))
member1.asInstanceOf[TermSymbol] setAlias member;
}
}
}
}
/** Mix in members of trait mixinClass into class clazz */
def mixinTraitMembers(mixinClass: Symbol): unit = {
// For all members of a trait's interface do:
for (val member <- mixinClass.info.decls.toList) {
if ((member hasFlag ACCESSOR) &&
(!(member hasFlag DEFERRED) || (member hasFlag lateDEFERRED))) {
// mixin field accessors
val member1 = addMember(
clazz,
member.cloneSymbol(clazz)
setPos clazz.pos
setFlag FINAL resetFlag (DEFERRED | lateDEFERRED))
if (!member.isSetter)
member.tpe match {
case MethodType(List(), ConstantType(_)) =>
// member is a constant; only getter is needed
;
case _ =>
// otherwise mixin a field as well
addMember(clazz,
clazz.newValue(member.pos, nme.getterToLocal(member.name))
setFlag (LOCAL | PRIVATE | member.getFlag(MUTABLE))
setInfo member.tpe.resultType)
}
} else if (member hasFlag SUPERACCESSOR) { // mixin super accessors
val member1 = addMember(clazz, member.cloneSymbol(clazz)) setPos clazz.pos
assert(member1.alias != NoSymbol, member1)
val alias1 = rebindSuper(clazz, member.alias, mixinClass)
member1.asInstanceOf[TermSymbol] setAlias alias1
} else if (member.isMethod && member.isModule && !(member hasFlag (LIFTED | BRIDGE))) {
// mixin objects: todo what happens with abstract objects?
addMember(clazz, member.cloneSymbol(clazz))
.setPos(clazz.pos)
.resetFlag(DEFERRED | lateDEFERRED)
}
}
}
for (val mc <- clazz.mixinClasses)
if (mc hasFlag lateINTERFACE) {
addLateInterfaceMembers(mc)
mixinTraitMembers(mc)
mixinImplClassMembers(implClass(mc), mc)
}
}
}
/** The info transform for this phase does the following:
* - The parents of every class are mapped from implementation class to interface
* - Implementation classes become modules that inherit nothing
* and that define all.
*
* @param sym ...
* @param tp ...
* @return ...
*/
override def transformInfo(sym: Symbol, tp: Type): Type = tp match {
case ClassInfoType(parents, decls, clazz) =>
var parents1 = parents
var decls1 = decls
if (!clazz.isPackageClass) {
atPhase(phase.next)(clazz.owner.info)
if (clazz.isImplClass) {
clazz setFlag lateMODULE
var sourceModule = clazz.owner.info.decls.lookup(sym.name.toTermName)
if (sourceModule != NoSymbol) {
sourceModule setPos sym.pos
sourceModule.flags = MODULE | FINAL
} else {
sourceModule = clazz.owner.newModule(
sym.pos, sym.name.toTermName, sym.asInstanceOf[ClassSymbol])
clazz.owner.info.decls enter sourceModule
}
sourceModule setInfo sym.tpe
assert(clazz.sourceModule != NoSymbol)//debug
parents1 = List()
decls1 = newScope(decls.toList filter isImplementedStatically)
} else if (!parents.isEmpty) {
parents1 = parents.head :: (parents.tail map toInterface)
}
}
//decls1 = atPhase(phase.next)(newScope(decls1.toList))//debug
if ((parents1 eq parents) && (decls1 eq decls)) tp
else ClassInfoType(parents1, decls1, clazz)
case MethodType(formals, restp) =>
toInterfaceMap(
if (isImplementedStatically(sym))
MethodType(toInterface(sym.owner.typeOfThis) :: formals, restp)
else
tp)
case _ =>
tp
}
// --------- term transformation -----------------------------------------------
protected def newTransformer(unit: CompilationUnit): Transformer =
new MixinTransformer
class MixinTransformer extends Transformer {
/** Within a static implementation method: the parameter referring to the
* current object undefined evrywhere else.
*/
private var self: Symbol = _
/** The rootContext used for typing */
private val rootContext =
erasure.NoContext.make(EmptyTree, RootClass, newScope)
/** The typer */
private var localTyper: erasure.Typer = _
/** Within a static implementation method: the interface type corresponding
* to the implementation module; undefined evrywhere else.
*/
private var enclInterface: Symbol = _
/** The first transform; called in a pre-order traversal at phase mixin
* (that is, every node is processed before its children.
* What transform does:
* - For every non-trait class, add all mixed in members to the class info.
* - For every trait, add all late interface members to the class info
* - For every static implementation method:
* - remove override flag
* - create a new method definition that also has a `self' parameter
* (which comes first)
* - Map implementation class types in type-apply's to their interfaces
* - Remove all fields in implementation classes
*/
private def preTransform(tree: Tree): Tree = {
val sym = tree.symbol
tree match {
case Template(parents, self, body) =>
localTyper = erasure.newTyper(rootContext.make(tree, currentOwner))
atPhase(phase.next)(currentOwner.owner.info)//todo: needed?
if (!currentOwner.isTrait) addMixedinMembers(currentOwner)
else if (currentOwner hasFlag lateINTERFACE) addLateInterfaceMembers(currentOwner)
tree
case DefDef(mods, name, tparams, List(vparams), tpt, rhs) if currentOwner.isImplClass =>
if (isImplementedStatically(sym)) {
sym setFlag notOVERRIDE
self = sym.newValue(sym.pos, nme.SELF)
.setFlag(PARAM)
.setInfo(toInterface(currentOwner.typeOfThis));
enclInterface = currentOwner.toInterface
val selfdef = ValDef(self) setType NoType
copy.DefDef(tree, mods, name, tparams, List(selfdef :: vparams), tpt, rhs)
} else {
EmptyTree
}
case Apply(tapp @ TypeApply(fn, List(arg)), List()) =>
if (arg.tpe.symbol.isImplClass) {
val ifacetpe = toInterface(arg.tpe)
arg.tpe = ifacetpe
tapp.tpe = MethodType(List(), ifacetpe)
tree.tpe = ifacetpe
}
tree
case ValDef(_, _, _, _) if currentOwner.isImplClass =>
EmptyTree
case _ =>
tree
}
}
/** Create an identifier which references self parameter.
*
* @param pos ...
*/
private def selfRef(pos: Position) =
gen.mkAttributedIdent(self) setPos pos
/** Replace a super reference by this or the self parameter, depending
* on whether we are in an implementation class or not.
* Leave all other trees unchanged */
private def transformSuper(qual: Tree) =
if (!qual.isInstanceOf[Super]) qual
else if (currentOwner.enclClass.isImplClass) selfRef(qual.pos)
else gen.mkAttributedThis(currentOwner.enclClass)
/** Create a static reference to given symbol <code>sym</code> of the
* form <code>M.sym</code> where M is the symbol's implementation module.
*/
private def staticRef(sym: Symbol) = {
sym.owner.info //todo: needed?
sym.owner.owner.info //todo: needed?
if (sym.owner.sourceModule == NoSymbol) {
assert(false, "" + sym + " in " + sym.owner + " in " + sym.owner.owner +
" " + sym.owner.owner.info.decls.toList)//debug
}
Select(gen.mkAttributedRef(sym.owner.sourceModule), sym)
}
/** Add all new definitions to a non-trait class
* These fall into the following categories:
* - for a trait interface:
* - abstract accessors for all fields in the implementation class
* - for a non-trait class:
* - A field for every in a mixin class
* - Setters and getters for such fields
* - module variables and module creators for every module in a mixin class
* (except if module is lifted -- in this case the module variable
* is local to some function, and the creator method is static.)
* - A super accessor for every super accessor in a mixin class
* - Forwarders for all methods that are implemented statically
* All superaccessors are completed with right-hand sides (@see completeSuperAccessor)
* @param clazz The class to which definitions are added
*/
private def addNewDefs(clazz: Symbol, stats: List[Tree]): List[Tree] = {
val newDefs = new ListBuffer[Tree]
/** Attribute given tree and anchor at given position */
def attributedDef(pos: Position, tree: Tree): Tree = {
if (settings.debug.value) log("add new def to " + clazz + ": " + tree)
localTyper.typed { atPos(pos) { tree } }
}
/** The position of given symbol, or, if this is undefined,
* the position of the current class. */
def position(sym: Symbol) =
if (sym.pos == NoPosition) clazz.pos else sym.pos
/** Add tree at given position as new definition */
def addDef(pos: Position, tree: Tree): unit =
newDefs += attributedDef(pos, tree)
/** Add new method definition.
*
* @param sym The method
* @param rhs A function that maps formal parameters to the method's
* right-hand side
*/
def addDefDef(sym: Symbol, rhs: List[Symbol] => Tree): unit =
addDef(position(sym), DefDef(sym, vparamss => rhs(vparamss.head)))
/** Add `newdefs' to `stats', removing any abstract method definitions
* in <code>stats</code> that are matched by some symbol defined in
* <code>newDefs</code>.
*/
def add(stats: List[Tree], newDefs: List[Tree]) = {
val newSyms = newDefs map (_.symbol)
def isNotDuplicate(tree: Tree) = tree match {
case DefDef(_, _, _, _, _, _) =>
val sym = tree.symbol;
!((sym hasFlag DEFERRED) &&
(newSyms exists (nsym => nsym.name == sym.name && (nsym.tpe matches sym.tpe))))
case _ =>
true
}
if (newDefs.isEmpty) stats
else newDefs ::: stats.filter(isNotDuplicate)
}
/** If `stat' is a superaccessor, complete it by adding a right-hand side.
* (Note: superaccessors are always abstract until this point.
* The method to call in a superaccessor is stored in the accessor symbol's alias field.
* The rhs is:
* super.A(xs) where A is the super accessor's alias and xs are its formal parameters.
* This rhs is typed and then mixin transformed.
*/
def completeSuperAccessor(stat: Tree) = stat match {
case DefDef(mods, name, tparams, List(vparams), tpt, EmptyTree)
if (stat.symbol hasFlag SUPERACCESSOR) =>
val rhs0 =
Apply(Select(Super(clazz, nme.EMPTY.toTypeName), stat.symbol.alias),
vparams map (vparam => Ident(vparam.symbol)))
val rhs1 = localTyper.typed(atPos(stat.pos)(rhs0), stat.symbol.tpe.resultType)
val rhs2 = atPhase(currentRun.mixinPhase)(transform(rhs1))
if (settings.debug.value)
log("complete super acc " + stat.symbol + stat.symbol.locationString +
" " + rhs1 + " " + stat.symbol.alias + stat.symbol.alias.locationString +
"/" + stat.symbol.alias.owner.hasFlag(lateINTERFACE))//debug
copy.DefDef(stat, mods, name, tparams, List(vparams), tpt, rhs2)
case _ =>
stat
}
// begin addNewDefs
// for all symbols `sym' in the class definition, which are mixed in:
for (val sym <- clazz.info.decls.toList) {
if (sym hasFlag MIXEDIN) {
if (clazz hasFlag lateINTERFACE) {
// if current class is a trait interface, add an abstract method for accessor `sym'
addDefDef(sym, vparamss => EmptyTree)
} else if (!clazz.isTrait) {
// if class is not a trait:
if ((sym hasFlag ACCESSOR) &&
(!(sym hasFlag DEFERRED) || (sym hasFlag lateDEFERRED))) {
// add accessor definitions
addDefDef(sym, vparams => {
val accessedRef = sym.tpe match {
case MethodType(List(), ConstantType(c)) => Literal(c)
case _ => Select(This(clazz), sym.accessed)
}
if (sym.isSetter) Assign(accessedRef, Ident(vparams.head))
else gen.mkCheckInit(accessedRef)
})
} else if (sym.isModule && !(sym hasFlag LIFTED | BRIDGE)) {
// add modules
val vdef = gen.mkModuleVarDef(sym)
addDef(position(sym), vdef)
addDef(position(sym), gen.mkModuleAccessDef(sym, vdef.symbol))
} else if (!sym.isMethod) {
// add fields
addDef(position(sym), ValDef(sym))
} else if (sym hasFlag SUPERACCESSOR) {
// add superaccessors
addDefDef(sym, vparams => EmptyTree)
} else {
// add forwarders
assert(sym.alias != NoSymbol, sym)
addDefDef(sym, vparams =>
Apply(staticRef(sym.alias), gen.mkAttributedThis(clazz) :: (vparams map Ident)))
}
}
}
}
var stats1 = add(stats, newDefs.toList)
if (!clazz.isTrait) stats1 = stats1 map completeSuperAccessor
stats1
}
/** The transform that gets applied to a tree after it has been completely
* traversed and possible modified by a preTransform.
* This step will
* - change every node type that refers to an implementation class to its
* corresponding interface, unless the node's symbol is an implementation class.
* - change parents of templates to conform to parents in the symbol info
* - add all new definitions to a class or interface
* - remove widening casts
* - change calls to methods which are defined only in implementation classes
* to static calls of methods in implementation modules (@see staticCall)
* - change super calls to methods in implementation classes to static calls
* (@see staticCall)
* - change `this' in implementation modules to references to the self parameter
* - refer to fields in some implementation class vie an abstract method in the interface.
*/
private def postTransform(tree: Tree): Tree = {
val sym = tree.symbol
// change every node type that refers to an implementation class to its
// corresponding interface, unless the node's symbol is an implementation class.
if (tree.tpe.symbol.isImplClass &&
((tree.symbol eq null) || !tree.symbol.isImplClass))
tree.tpe = toInterface(tree.tpe);
tree match {
case Template(parents, self, body) =>
// change parents of templates to conform to parents in the symbol info
val parents1 = currentOwner.info.parents map (t => TypeTree(t) setPos tree.pos)
// add all new definitions to current class or interface
val body1 = addNewDefs(currentOwner, body)
copy.Template(tree, parents1, self, body1)
case Apply(TypeApply(sel @ Select(qual, name), List(targ)), List())
if (tree.symbol == Object_asInstanceOf && (qual.tpe <:< targ.tpe)) =>
// remove widening casts
qual
case Apply(Select(qual, _), args) =>
/** Changes <code>qual.m(args)</code> where m refers to an implementation
* class method to Q.m(S, args) where Q is the implementation module of
* <code>m</code> and S is the self parameter for the call, which
* is determined as follows:
* - if qual != super, qual itself
* - if qual == super, and we are in an implementation class,
* the current self parameter.
* - if qual == super, and we are not in an implementation class, `this'
*/
def staticCall(target: Symbol) = {
if (target == NoSymbol)
assert(false, "" + sym + ":" + sym.tpe + " " + sym.owner + " " + implClass(sym.owner) + " " + implClass(sym.owner).info.member(sym.name) + " " + atPhase(phase.prev)(implClass(sym.owner).info.member(sym.name).tpe) + " " + phase);//debug
localTyper.typed {
atPos(tree.pos) {
Apply(staticRef(target), transformSuper(qual) :: args)
}
}
}
if (isStaticOnly(sym)) {
// change calls to methods which are defined only in implementation
// classes to static calls of methods in implementation modules
staticCall(sym)
} else qual match {
case Super(_, mix) =>
// change super calls to methods in implementation classes to static calls.
// Transform references super.m(args) as follows:
// - if `m' refers to a trait, insert a static call to the correspondign static
// implementation
// - otherwise return tree unchanged
if (mix == nme.EMPTY.toTypeName && currentOwner.enclClass.isImplClass)
assert(false, "illegal super in trait: " + currentOwner.enclClass + " " + tree);
if (sym.owner hasFlag lateINTERFACE) {
if (sym.hasFlag(ACCESSOR)) {
assert(args.isEmpty)
val sym1 = sym.overridingSymbol(currentOwner.enclClass)
localTyper.typed {
atPos(tree.pos) {
Apply(Select(transformSuper(qual), sym1), List())
}
}
} else {
staticCall(atPhase(phase.prev)(sym.overridingSymbol(implClass(sym.owner))))
}
} else {
assert(!currentOwner.enclClass.isImplClass)
tree
}
case _ =>
tree
}
case This(_) if tree.symbol.isImplClass =>
// change `this' in implementation modules to references to the self parameter
assert(tree.symbol == currentOwner.enclClass)
selfRef(tree.pos)
case Select(Super(_, _), name) =>
tree
case Select(qual, name) if sym.owner.isImplClass && !isStaticOnly(sym) =>
// refer to fields in some implementation class via an abstract
// getter in the interface.
if (sym.isMethod)
assert(false, "no method allowed here: " + sym + sym.isImplOnly +
" " + flagsToString(sym.flags))
val getter = sym.getter(enclInterface)
assert(getter != NoSymbol)
localTyper.typed {
atPos(tree.pos) {
Apply(Select(qual, getter), List())
}
}
case Assign(Apply(lhs @ Select(qual, _), List()), rhs) =>
// assign to fields in some implementation class via an abstract
// setter in the interface.
localTyper.typed {
atPos(tree.pos) {
Apply(Select(qual, lhs.symbol.setter(enclInterface)) setPos lhs.pos, List(rhs))
}
}
case _ =>
tree
}
}
/** The main transform method.
* This performs pre-order traversal preTransform at mixin phase;
* when coming back, it performs a postTransform at phase after.
*/
override def transform(tree: Tree): Tree = {
try { //debug
val tree1 = super.transform(preTransform(tree))
atPhase(phase.next)(postTransform(tree1))
} catch {
case ex: Throwable =>
if (settings.debug.value) Console.println("exception when traversing " + tree)
throw ex
}
}
}
}
