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/* NSC -- new scala compiler
* Copyright 2005 LAMP/EPFL
* @author
*/
// $Id$
package scala.tools.nsc.transform;
import symtab._;
import Flags._;
import util.ListBuffer;
import collection.mutable.HashMap;
abstract class AddInterfaces extends InfoTransform {
import global._; // the global environment
import definitions._; // standard classes and methods
import posAssigner.atPos; // for filling in tree positions
override def phaseNewFlags: long = lateDEFERRED | lateINTERFACE;
// Type transformation
def erasedTypeRef(sym: Symbol): Type;
private val implClassMap = new HashMap[Symbol, Symbol];
private val implMethodMap = new HashMap[Symbol, Symbol];
override def newPhase(prev: scala.tools.nsc.Phase): StdPhase = {
implClassMap.clear;
implMethodMap.clear;
super.newPhase(prev)
}
private def needsImplMethod(sym: Symbol): boolean = (
sym.isMethod && isInterfaceMember(sym) &&
(!(sym hasFlag (DEFERRED | SUPERACCESSOR)) || (sym hasFlag lateDEFERRED))
);
private def isInterfaceMember(sym: Symbol): boolean = {
sym.info; // to set lateMETHOD flag if necessary
(sym.isType ||
sym.isMethod && !(sym hasFlag (PRIVATE | BRIDGE | LABEL)) &&
!sym.isConstructor && !sym.isImplOnly)
}
def implClass(iface: Symbol): Symbol = implClassMap.get(iface) match {
case Some(c) => c
case None =>
atPhase(currentRun.erasurePhase) {
val implName = nme.implClassName(iface.name);
var impl = if (iface.owner.isClass) iface.owner.info.decl(implName) else NoSymbol;
if (impl == NoSymbol) {
impl = iface.cloneSymbolImpl(iface.owner);
impl.name = implName;
if (iface.owner.isClass) iface.owner.info.decls enter impl
}
impl setPos iface.pos;
impl.flags = iface.flags & ~(INTERFACE | lateINTERFACE) | IMPLCLASS;
impl setInfo new LazyImplClassType(iface);
implClassMap(iface) = impl;
if (settings.debug.value) log("generating impl class " + impl + " in " + iface.owner);//debug
impl
}
}
private class LazyImplClassType(iface: Symbol) extends LazyType {
def implDecls(implClass: Symbol, ifaceDecls: Scope): Scope = {
val decls = new Scope();
for (val sym <- ifaceDecls.elements) {
if (isInterfaceMember(sym)) {
if (needsImplMethod(sym)) {
val impl = sym.cloneSymbol(implClass).setInfo(sym.info).resetFlag(lateDEFERRED);
if (!impl.isExternal) implMethodMap(sym) = impl;
decls enter impl;
sym setFlag lateDEFERRED
}
} else {
sym.owner = implClass;
decls enter sym;
}
}
decls
}
override def complete(sym: Symbol): unit = {
def implType(tp: Type): Type = tp match {
case ClassInfoType(parents, decls, _) =>
//ClassInfoType(traitToImplClass(parents) ::: List(iface.tpe), implDecls(sym, decls), sym)
ClassInfoType(
ObjectClass.tpe :: (parents.tail map traitToImplClass) ::: List(iface.tpe),
implDecls(sym, decls),
sym)
case PolyType(tparams, restpe) =>
PolyType(tparams, implType(restpe))
}
sym.setInfo(atPhase(currentRun.erasurePhase)(implType(iface.info)));
}
override def load(clazz: Symbol): unit = complete(clazz)
}
private def traitToImplClass(tp: Type): Type = tp match {
case TypeRef(pre, sym, args) if (sym.needsImplClass) =>
typeRef(pre, implClass(sym), args)
case _ =>
tp
}
def transformTraitInfo(tp: Type): Type = tp match {
case ClassInfoType(parents, decls, clazz) =>
if (clazz.needsImplClass) {
clazz setFlag lateINTERFACE;
implClass(clazz) // generate an impl class
}
val parents1 =
if (parents.isEmpty) List()
else {
assert(!parents.head.symbol.isTrait || clazz == RepeatedParamClass, clazz);
if (clazz hasFlag INTERFACE) erasedTypeRef(ObjectClass) :: parents.tail
else if (clazz.isImplClass || clazz == ArrayClass) parents
else parents map traitToImplClass
}
val decls1 = if (clazz hasFlag INTERFACE) new Scope(decls.toList filter isInterfaceMember)
else decls;
if ((parents1 eq parents) && (decls1 eq decls)) tp
else ClassInfoType(parents1, decls1, clazz)
case _ =>
tp
}
// Tree transformation --------------------------------------------------------------
private class ChangeOwnerAndReturnTraverser(oldowner: Symbol, newowner: Symbol)
extends ChangeOwnerTraverser(oldowner, newowner) {
override def traverse(tree: Tree): unit = {
tree match {
case Return(expr) =>
if (tree.symbol == oldowner) tree.symbol = newowner;
case _ =>
}
super.traverse(tree)
}
}
private def ifaceMemberDef(tree: Tree): Tree =
if (!tree.isDef || !isInterfaceMember(tree.symbol)) EmptyTree
else if (needsImplMethod(tree.symbol)) DefDef(tree.symbol, vparamss => EmptyTree)
else tree;
private def ifaceTemplate(templ: Template): Template =
copy.Template(templ, templ.parents, templ.body map ifaceMemberDef);
private def implMethodDef(tree: Tree, ifaceMethod: Symbol): Tree =
implMethodMap.get(ifaceMethod) match {
case Some(implMethod) =>
tree.symbol = implMethod;
new ChangeOwnerAndReturnTraverser(ifaceMethod, implMethod)(tree)
case None =>
throw new Error("implMethod missing for " + ifaceMethod)
}
private def implMemberDef(tree: Tree): Tree =
if (!tree.isDef || !isInterfaceMember(tree.symbol)) tree
else if (needsImplMethod(tree.symbol)) implMethodDef(tree, tree.symbol)
else EmptyTree;
private def implTemplate(clazz: Symbol, templ: Template): Template = atPos(templ.pos){
val templ1 = Template(templ.parents, templ.body map implMemberDef)
.setPos(templ.pos)
.setSymbol(clazz.newLocalDummy(templ.pos));
new ChangeOwnerTraverser(templ.symbol.owner, clazz)(
new ChangeOwnerTraverser(templ.symbol, templ1.symbol)(templ1))
}
def implClassDefs(trees: List[Tree]): List[Tree] = {
val buf = new ListBuffer[Tree];
for (val tree <- trees)
tree match {
case ClassDef(_, _, _, _, impl) =>
if (tree.symbol.needsImplClass)
buf += {
val clazz = implClass(tree.symbol).initialize;
ClassDef(clazz, implTemplate(clazz, impl))
}
case _ =>
}
buf.toList
}
protected val traitTransformer = new Transformer {
override def transformStats(stats: List[Tree], exprOwner: Symbol): List[Tree] =
(super.transformStats(stats, exprOwner) :::
super.transformStats(implClassDefs(stats), exprOwner));
override def transform(tree: Tree): Tree = {
val tree1 = tree match {
case ClassDef(mods, name, tparams, tpt, impl) =>
if (tree.symbol.needsImplClass) {
implClass(tree.symbol).initialize; // to force lateDEFERRED flags
copy.ClassDef(tree, mods | INTERFACE, name, tparams, tpt, ifaceTemplate(impl))
}
else tree
case Template(parents, body) =>
val parents1 = tree.symbol.owner.info.parents map (t => TypeTree(t) setPos tree.pos);
copy.Template(tree, parents1, body)
case This(_) =>
if (tree.symbol.needsImplClass) {
val impl = implClass(tree.symbol);
var owner = currentOwner;
while (owner != tree.symbol && owner != impl) owner = owner.owner;
if (owner == impl) This(impl) setPos tree.pos
else tree
} else tree
case Super(qual, mix) =>
val mix1 =
if (mix == nme.EMPTY.toTypeName) mix
else {
val ps = atPhase(currentRun.erasurePhase) {
tree.symbol.info.parents dropWhile (p => p.symbol.name != mix)
}
assert(!ps.isEmpty, tree);
if (ps.head.symbol.needsImplClass) implClass(ps.head.symbol).name
else mix
}
if (tree.symbol.needsImplClass) Super(implClass(tree.symbol), mix1) setPos tree.pos
else copy.Super(tree, qual, mix1)
case _ =>
tree
}
super.transform(tree1)
}
}
}
/*
val ensureNoEscapes = new TypeTraverser {
def ensureNoEscape(sym: Symbol): unit = {
if (sym.hasFlag(PRIVATE)) {
var o = currentOwner;
while (o != NoSymbol && o != sym.owner && !o.isLocal && !o.hasFlag(PRIVATE))
o = o.owner;
if (o == sym.owner) sym.makeNotPrivate(base);
}
}
def traverse(t: Type): TypeTraverser = {
t match {
case TypeRef(qual, sym, args) =>
ensureNoEscape(sym);
mapOver(t);
case ClassInfoType(parents, decls, clazz) =>
parents foreach { p => traverse; () }
traverse(t.typeOfThis);
case _ =>
mapOver(t)
}
this
}
}
*/
|
