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/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
** **
\* */
// $Id$
package scalac.transformer;
import scalac.Global;
import scalac.util.Name;
import scalac.ast.Tree;
import Tree.*;
import scalac.ast.Transformer;
import scalac.symtab.Type;
import scalac.symtab.Symbol;
import scalac.symtab.TermSymbol;
import scalac.symtab.Scope;
import scalac.symtab.Kinds;
import scalac.symtab.Modifiers;
import java.util.HashMap;
import java.util.HashSet;
import java.util.ArrayList;
import scalac.util.Debug;
/**
* 1. For each class add a single method (DefDef) designated as
* constructor whose parameters are the class parameters. The
* constructor contains:
* - call to the constructor of the supertype with the appropriate arguments
* - initialize the fields corresponding to the class ValDefs
* - the bodies of the class level expressions;
* they are also removed from the ClassDef body
*
* 2. The right hand sides of the ValDefs are left empty
*
* 3. Substitute the appropriate constructor symbol into the
* 'new' expressions
*
* @author Nikolay Mihaylov
* @version 1.2
*/
public class AddConstructors extends Transformer {
public final static Name CTOR_N = Name.fromString("<init>");
// True iff we generate code for INT backend.
protected final boolean forINT;
// True iff we generate code for JVM backend.
protected final boolean forJVM;
// True iff we generate code for MSIL backend.
protected final boolean forMSIL;
final HashMap constructors;
public AddConstructors(Global global, AddConstructorsPhase descr, HashMap constructors) {
super(global, descr);
this.constructors = constructors;
this.forINT = global.target == global.TARGET_INT;
this.forJVM = global.target == global.TARGET_JVM;
this.forMSIL = global.target == global.TARGET_MSIL;
}
/** return new constructor symbol if it isn't already defined
*/
Symbol getConstructor(Symbol classConstr) {
return getConstructor(classConstr,
(((Type.MethodType)classConstr.info()).vparams));
}
Symbol getConstructor(Symbol classConstr, Symbol[] paramSyms) {
//assert (classConstr.flags & Modifiers.CONSTRUCTOR) != 0:
// assert classConstr.isConstructor() :
// "Constructor functions not implemented yet! " +
// Debug.show(classConstr);
Symbol constr = (Symbol) constructors.get(classConstr);
if (constr == null) {
Symbol clazz = classConstr.primaryConstructorClass();
int flags = forJVM
? classConstr.flags & (Modifiers.PRIVATE | Modifiers.PROTECTED)
: classConstr.flags;
constr =
new TermSymbol(classConstr.pos, CTOR_N, clazz, flags);
constr.setInfo(Type.MethodType
(paramSyms, //((Type.MethodType)classConstr.info()).vparams,
forJVM || forMSIL
? global.definitions.UNIT_TYPE
: clazz.type()).erasure());
constructors.put(classConstr, constr);
constructors.put(constr, constr);
}
return constr;
}
/** process the tree
*/
public Tree transform(Tree tree) {
Symbol treeSym = tree.symbol();
switch (tree) {
case ClassDef(_, _, _, ValDef[][] vparams, _, //:
Template(Tree[] baseClasses, Tree[] body)):
if (treeSym.isInterface())
return tree;
assert treeSym.name.isTypeName();
/*
System.out.println("Class parameters in the tree:");
Param[] pparams = vparams[0];
for (int i = 0; i < pparams.length; i++)
System.out.println("\t" + Debug.show(pparams[i].symbol()));
System.out.println("Class parameters in the constructor:");
Symbol[] sparams = ((Type.MethodType)treeSym.constructor().info()).vparams;
for (int i = 0; i < sparams.length; i++)
System.out.println("\t" + Debug.show(sparams[i]));
*/
Symbol[] paramSyms = new Symbol[vparams[0].length];
for (int i = 0; i < paramSyms.length; i++)
paramSyms[i] = vparams[0][i].symbol();
ArrayList constrBody = new ArrayList();
ArrayList classBody = new ArrayList();
Symbol constrSym = getConstructor(treeSym.constructor(), paramSyms);
Scope classScope = new Scope();
classScope.enter(constrSym);
// inline the call to the super constructor
Type superType = treeSym.parents()[0];
if ( !forINT || !superType.symbol().isJava())
switch (baseClasses[0]) {
case Apply(Tree fun, Tree[] args):
int pos = baseClasses[0].pos;
Tree superConstr = gen.Select
(gen.Super(pos, superType),
getConstructor(fun.symbol()));
constrBody.add(gen.Apply(superConstr, transform(args)));
break;
default: assert false;
}
// for every ValDef move the initialization code into the constructor
for (int i = 0; i < body.length; i++) {
Tree t = body[i];
if (t.definesSymbol()) {
Symbol sym = t.symbol();
switch (t) {
case ValDef(_,_,_,Tree rhs):
if (rhs != Tree.Empty) {
// !!!FIXME: revert to this.whatever when the bug is fixed
//Tree ident = gen.Select(gen.This(t.pos, treeSym), sym);
Tree ident = gen.Ident(sym);
constrBody.add(gen.Assign(t.pos, ident, transform(rhs)));
t = gen.ValDef(sym, Tree.Empty);
}
break;
}
classBody.add(transform(t));
classScope.enter(sym);
} else
// move every class-level expression into the constructor
constrBody.add(transform(t));
}
// add result expression consistent with the
// result type of the constructor
//if (! forJVM)
// constrBody.add(gen.This(tree.pos, treeSym));
Tree constrTree = constrBody.size() > 1 ?
gen.Block((Tree[])constrBody.toArray(new Tree[constrBody.size()])):
(Tree) constrBody.get(0);
// add constructor definition to the body of the class
classBody.add(gen.DefDef(tree.pos, constrSym, constrTree));
// strip off the class constructor from parameters
switch (treeSym.constructor().info()) {
case MethodType(_, Type result):
treeSym.constructor().
updateInfo(Type.MethodType(Symbol.EMPTY_ARRAY, result));
break;
default : assert false;
}
Type classType =
// Type.CompoundType(treeSym.parents(), classScope);
Type.compoundType(treeSym.parents(), classScope, treeSym);
Symbol classSym = treeSym.updateInfo(classType);
//fixConstructor(classSym);
Tree[] newBody = (Tree[]) classBody.toArray(Tree.EMPTY_ARRAY);
return gen.ClassDef(classSym, newBody);
// Substitute the constructor into the 'new' expressions
case New(Template(Tree[] baseClasses, _)):
Tree base = baseClasses[0];
switch (base) {
case Apply(Tree fun, Tree[] args):
return gen.New(copy.Apply
(base,
gen.Ident(base.pos, getConstructor(fun.symbol())),
transform(args)));
default:
assert false;
}
break;
// is this still needed?
case Ident(Name name):
if (treeSym.isConstructor()) {
Debug.abort("Not implemented yet: using class constructor as function!");
//return gen.mkId(tree.pos, getConstructor(treeSym));
}
//System.out.println("Processing " + Debug.show(treeSym));
break;
// is this still needed?
case Select(Tree qualifier, Name selector):
if (treeSym.isConstructor()) {
Debug.abort("Not implemented yet: using class constructor as function!");
//return gen.mkSel(tree.pos, transform(qualifier), getConstructor(treeSym));
}
break;
} // switch(tree)
return super.transform(tree);
} // transform()
// /** Given a symbol of a class it strips off the parameters
// * from the MethodType of the constructor of that class
// * and all its superclasses
// */
// public void fixConstructor(Symbol clazz) {
// if (clazz != global.definitions.ANY_CLASS) {
// switch (clazz.constructor().info()) {
// case MethodType(Symbol[] params, Type result):
// if (params.length > 0) {
// clazz.constructor().updateInfo
// (Type.MethodType(Symbol.EMPTY_ARRAY, result));
// }
// //fixConstructor(clazz.basetypes()[0].symbol());
// break;
// default:
// assert false : "Constructor should have a method type!";
// }
// }
// }
} // class AddConstructors
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