/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
\* */
// $Id$
// TODO find a good way to change symbol flags (PRIVATE, DEFERRED,
// INTERFACE). In particular find how to make sure that the
// modifications are not made too early, for example before the symbol
// is cloned.
package scalac.transformer;
import scalac.*;
import ch.epfl.lamp.util.*;
import scalac.ast.*;
import scalac.symtab.*;
import scalac.util.*;
import Tree.*;
import java.util.*;
/**
* Add, for each class, an interface with the same name, to be used
* later by mixin expansion. More specifically:
*
* - at the end of the name of every class, the string "$class" is
* added,
*
* - an interface with the original name of the class is created, and
* contains all directly bound members of the class (as abstract
* members),
*
* - the interface is added to the mixin base classes of the class.
*
* @author Michel Schinz
* @version 1.0
*/
class AddInterfaces extends Transformer {
protected AddInterfacesPhase phase;
protected Definitions defs;
public AddInterfaces(Global global, AddInterfacesPhase phase) {
super(global, global.make);
this.phase = phase;
this.defs = global.definitions;
}
protected LinkedList/*<Pair<Symbol,Symbol>>*/ ownerSubstStack =
new LinkedList();
protected Pair/*<Symbol,Symbol>*/ ownerSubst = null;
protected SymbolSubstTypeMap typeSubst = null;
protected Type.SubstThisMap thisTypeSubst = null;
protected LinkedList/*<List<Tree>>*/ bodyStack = new LinkedList();
public Tree[] transform(Tree[] trees) {
List newTrees = new ArrayList();
bodyStack.addFirst(newTrees);
for (int i = 0; i < trees.length; ++i)
newTrees.add(transform(trees[i]));
bodyStack.removeFirst();
return (Tree[]) newTrees.toArray(new Tree[newTrees.size()]);
}
public Tree transform(Tree tree) {
// Update tree type, to take into account the new (type)
// symbols of enclosing classes / methods.
Type newTp = tree.type();
if (typeSubst != null) newTp = typeSubst.apply(newTp);
if (thisTypeSubst != null) newTp = thisTypeSubst.apply(newTp);
tree.setType(newTp);
if (tree.definesSymbol() && !(tree instanceof ClassDef)) {
// Update symbol's owner, if needed.
Symbol sym = tree.symbol();
if (ownerSubst != null && ownerSubst.fst == sym.owner())
sym.setOwner((Symbol)ownerSubst.snd);
// Update symbol's type. Do that only for symbols which do
// not belong to a class, since the type of these (i.e.
// class members) has been changed during cloning
// operation.
if (! (sym.owner().isClass() || thisTypeSubst == null))
sym.updateInfo(typeSubst.apply(sym.info()));
}
switch (tree) {
case ClassDef(_,_,_,_,_,_): {
Symbol sym = tree.symbol();
if (phase.needInterface(sym)) {
ClassDef classDef = (ClassDef)tree;
Symbol ifaceSym = sym;
Symbol classSym = phase.getClassSymbol(ifaceSym);
List/*<Tree>*/ enclosingBody = (List)bodyStack.getFirst();
enclosingBody.add(makeInterface(classDef));
typeSubst = phase.getClassSubst(classSym);
Tree newTree = makeClass(classDef);
typeSubst = null;
return newTree;
} else
return super.transform(tree);
}
case DefDef(int mods,
Name name,
AbsTypeDef[] tparams,
ValDef[][] vparams,
Tree tpe,
Tree rhs): {
Symbol sym = tree.symbol();
Symbol owner = sym.owner();
Tree newTree;
if (owner.isClass() && phase.needInterface(owner)) {
Symbol classOwner = phase.getClassSymbol(owner);
Map ownerMemberMap = phase.getClassMemberMap(classOwner);
Symbol newSym = (Symbol)ownerMemberMap.get(sym);
assert newSym != null;
global.nextPhase();
typeSubst.insertSymbol(sym.typeParams(), newSym.typeParams());
typeSubst.insertSymbol(sym.valueParams(), newSym.valueParams());
global.prevPhase();
pushOwnerSubst(sym, newSym);
newTree = gen.DefDef(newSym, transform(rhs));
popOwnerSubst();
typeSubst.removeSymbol(sym.valueParams());
typeSubst.removeSymbol(sym.typeParams());
} else
newTree = super.transform(tree);
return newTree;
}
case This(_): {
// Use class symbol for references to "this".
Symbol classThisSym = phase.getClassSymbol(tree.symbol());
return gen.This(tree.pos, classThisSym);
}
case Select(Super(_, _), _): {
// Use class member symbols for references to "super".
Symbol sym = tree.symbol();
Symbol classOwner = phase.getClassSymbol(sym.owner());
Map ownerMemberMap = phase.getClassMemberMap(classOwner);
if (ownerMemberMap != null && ownerMemberMap.containsKey(sym)) {
Symbol newSym = (Symbol)ownerMemberMap.get(sym);
return gen.Select(((Select)tree).qualifier, newSym);
} else
return super.transform(tree);
}
case Select(Tree qualifier, _): {
Symbol sym = tree.symbol();
if (sym.isConstructor()) {
// If the constructor now refers to the interface
// constructor, use the class constructor instead.
Symbol clsSym = sym.constructorClass();
if (phase.needInterface(clsSym))
return gen.Select(qualifier,
phase.getClassSymbol(clsSym).primaryConstructor());
else
return super.transform(tree);
} else {
qualifier = transform(qualifier);
Symbol owner = sym.owner();
if (owner.isClass()
&& owner.isJava() && !owner.isInterface()
&& owner != defs.ANY_CLASS
&& owner != defs.ANYREF_CLASS
&& owner != defs.JAVA_OBJECT_CLASS) {
Type qualifierType = qualifier.type().bound();
if (phase.needInterface(qualifierType.symbol())) {
Type castType = qualifierType.baseType(owner);
qualifier =
gen.Apply(
gen.TypeApply(
gen.Select(qualifier, defs.AS),
new Tree[] {
gen.mkType(tree.pos, castType)}),
Tree.EMPTY_ARRAY);
}
}
return copy.Select(tree, sym, qualifier);
}
}
case Ident(_): {
Symbol sym = tree.symbol();
if (sym.isConstructor()) {
// If the constructor now refers to the interface
// constructor, use the class constructor instead.
Symbol clsSym = sym.constructorClass();
if (phase.needInterface(clsSym))
return gen.Ident(phase.getClassSymbol(clsSym).primaryConstructor());
else
return super.transform(tree);
} else if (typeSubst != null) {
Symbol newSym = (Symbol)typeSubst.lookupSymbol(tree.symbol());
if (newSym != null)
return gen.Ident(newSym);
else
return super.transform(tree);
} else {
return super.transform(tree);
}
}
case New(Template templ): {
Tree.New newTree = (Tree.New)super.transform(tree);
Symbol ifaceSym = newTree.type.unalias().symbol();
if (phase.needInterface(ifaceSym)) {
Map clsMap = new HashMap();
Symbol classSym = phase.getClassSymbol(ifaceSym);
clsMap.put(ifaceSym, classSym);
clsMap.put(ifaceSym.primaryConstructor(), classSym.primaryConstructor());
SymbolSubstTypeMap clsSubst =
new SymbolSubstTypeMap(clsMap, Collections.EMPTY_MAP);
newTree.setType(clsSubst.apply(newTree.type));
newTree.templ.setType(clsSubst.apply(newTree.templ.type));
Tree.Apply parent = (Tree.Apply)newTree.templ.parents[0];
parent.setType(clsSubst.apply(parent.type));
parent.fun.setType(clsSubst.apply(parent.fun.type));
}
return newTree;
}
case Template(_,_): {
Symbol sym = tree.symbol();
if (sym != Symbol.NONE) {
Symbol newDummySymbol = sym.cloneSymbol();
pushOwnerSubst(sym, newDummySymbol);
Tree newTemplate = super.transform(tree);
popOwnerSubst();
return newTemplate;
} else
return super.transform(tree);
}
default:
return super.transform(tree);
}
}
protected Tree makeInterface(ClassDef classDef) {
Template classImpl = classDef.impl;
Tree[] classBody = classImpl.body;
TreeList ifaceBody = new TreeList();
for (int i = 0; i < classBody.length; ++i) {
Tree t = classBody[i];
Symbol tSym = t.symbol();
if (!t.definesSymbol() || !phase.memberGoesInInterface(tSym))
continue;
if (tSym.isClass())
ifaceBody.append(transform(new Tree[] { t }));
else if (tSym.isType())
ifaceBody.append(t);
else if (tSym.isMethod())
ifaceBody.append(gen.DefDef(tSym, Tree.Empty));
else
throw Debug.abort("don't know what to do with this ", t);
}
return gen.ClassDef(classDef.symbol(), ifaceBody.toArray());
}
protected Tree makeClass(ClassDef classDef) {
Symbol ifaceSym = classDef.symbol();
Symbol classSym = phase.getClassSymbol(ifaceSym);
TreeList newClassBody = new TreeList();
Template classImpl = classDef.impl;
Tree[] classBody = classImpl.body;
Map classMemberMap = phase.getClassMemberMap(classSym);
assert thisTypeSubst == null;
thisTypeSubst = new Type.SubstThisMap(ifaceSym, classSym);
for (int i = 0; i < classBody.length; ++i) {
Tree t = classBody[i];
Symbol tSym = t.symbol();
if (t.definesSymbol() && !classMemberMap.containsKey(tSym))
continue;
Tree newT = transform(t);
if (t.definesSymbol() && classMemberMap.containsKey(tSym))
newT.setSymbol((Symbol)classMemberMap.get(tSym));
newClassBody.append(newT);
}
thisTypeSubst = null;
Tree[][] oldParentArgs = extractParentArgs(classImpl.parents);
Tree[][] parentArgs = new Tree[oldParentArgs.length + 1][];
System.arraycopy(oldParentArgs, 0, parentArgs, 0, oldParentArgs.length);
parentArgs[oldParentArgs.length] = Tree.EMPTY_ARRAY;
global.nextPhase();
Type[] newParents = classSym.parents();
global.prevPhase();
Tree[] newClassParents =
gen.mkParentConstrs(classDef.pos, newParents, parentArgs);
Symbol local = classDef.impl.symbol();
local.setOwner(classSym);
return gen.ClassDef(classSym, newClassParents, local, newClassBody.toArray());
}
protected Tree[][] extractParentArgs(Tree[] parents) {
Tree[][] pArgs = new Tree[parents.length][];
for (int i = 0; i < parents.length; ++i) {
switch(parents[i]) {
case Apply(_, Tree[] args): pArgs[i] = transform(args); break;
default: throw Debug.abort("unexpected parent constr. ", parents[i]);
}
}
return pArgs;
}
protected void pushOwnerSubst(Symbol from, Symbol to) {
ownerSubstStack.addFirst(ownerSubst);
ownerSubst = new Pair(from, to);
}
protected void popOwnerSubst() {
ownerSubst = (Pair)ownerSubstStack.removeFirst();
}
}