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/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
\* */
// $OldId: ExpandMixinsPhase.java,v 1.8 2002/05/02 10:59:35 schinz Exp $
// $Id$
package scalac.transformer;
import java.util.Map;
import java.util.HashMap;
import scalac.Global;
import scalac.Phase;
import scalac.PhaseDescriptor;
import scalac.Unit;
import scalac.ast.Tree;
import scalac.ast.Tree.Template;
import scalac.ast.Traverser;
import scalac.ast.Transformer;
import scalac.symtab.Symbol;
import scalac.symtab.Type;
import scalac.checkers.*;
import scalac.util.Debug;
// TODO do not copy hidden members which are not accessible via
// "super".
/**
* A phase to expand mixins using code copying. We assume that links
* to outer classes have been made explicit by a previous phase.
*/
public class ExpandMixinsPhase extends Phase {
//########################################################################
// Private Fields
/** A map from classes to their interface */
private final Map/*<Symbol,Symbol>*/ interfaces;
/** A map from classes to their expanded template */
private final Map/*<Symbol,Template>*/ expansions;
/** A map from classes to their original (unexpanded) template */
private final Map/*<Symbol,Template>*/ templates;
/** A traverser that collects class definitions */
private final Traverser collector;
/** A transformer that expands classes that have mixins */
private final Transformer expander;
//########################################################################
// Public Constructors
/** Initializes this instance. */
public ExpandMixinsPhase(Global global, PhaseDescriptor descriptor) {
super(global, descriptor);
Phase addinterfaces = global.PHASE.ADDINTERFACES.phase();
this.interfaces = ((AddInterfacesPhase)addinterfaces).classToIFace;
this.expansions = new HashMap();
this.templates = new HashMap();
this.collector = new Collector();
this.expander = new Expander(global);
}
//########################################################################
// Public Methods
public void apply(Unit[] units) {
collector.traverse(units);
expander.apply(units);
assert templates.isEmpty() : templates.keySet();
}
public Type transformInfo(Symbol symbol, Type type) {
// !!! make this work and remove *1 in ClassExpander
// if (!symbol.isJava() && symbol.isClass() && !symbol.isInterface())
// type = getExpandedTemplate(symbol).type();
return type;
}
public Checker[] postCheckers(Global global) {
return new Checker[] {
new CheckSymbols(global),
new CheckTypes(global),
new CheckOwners(global),
new CheckNames(global)
};
}
//########################################################################
// Private Methods
private Template getExpandedTemplate(Symbol clasz) {
if (global.debug) global.log("get expanded " + clasz + " in " + clasz.owner());
Template template = (Template)expansions.get(clasz);
if (template == null) {
template = (Template)templates.remove(clasz);
assert template != null : Debug.show(clasz);
template = expandTemplate(clasz, expander.transform(template));
expansions.put(clasz, template);
}
return template;
}
private Template expandTemplate(Symbol clasz, Template template) {
assert Debug.log("expanding ", clasz);
ClassExpander expander = null;
Type[] parents = clasz.parents();
for (int i = parents.length - 1; i > 0; --i) {
Symbol parent = parents[i].symbol();
if (parent.isInterface()) continue;
if (expander == null)
expander = new ClassExpander(global, clasz, template);
assert Debug.log("expanding ", clasz, ": inlining ", parent);
expander.inlineMixin(i, parents[i], (Symbol)interfaces.get(parent),
getExpandedTemplate(parent));
}
return expander == null ? template : expander.getTemplate();
}
//########################################################################
// Private Class - Collector
private class Collector extends Traverser {
public void traverse(Tree tree) {
switch(tree) {
case ClassDef(_, _, _, _, _, Template template):
Symbol clasz = tree.symbol();
if (!clasz.isInterface()) templates.put(clasz, template);
traverse(template.body);
return;
case PackageDef(_, Template(_, Tree[] body)):
traverse(body);
return;
}
}
}
//########################################################################
// Private Class - Expander
private class Expander extends Transformer {
public Expander(Global global) {
super(global);
}
public Tree transform(Tree tree) {
switch (tree) {
case ClassDef(_, _, _, _, _, _):
Symbol clasz = tree.symbol();
if (clasz.isInterface()) return super.transform(tree);
return gen.ClassDef(clasz, getExpandedTemplate(clasz));
case PackageDef(_, _):
return super.transform(tree);
case Template(_, _):
return super.transform(tree);
default:
return tree;
}
}
}
//########################################################################
}
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