/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: CastExpr.java,v 1.23 2004/12/15 17:35:38 jycli Exp $
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.IF_ICMPNE;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.SIPUSH;
import org.apache.xalan.xsltc.compiler.util.BooleanType;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.MultiHashtable;
import org.apache.xalan.xsltc.compiler.util.NodeType;
import org.apache.xalan.xsltc.compiler.util.ResultTreeType;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
import org.apache.xml.dtm.Axis;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
* @author Morten Jorgensen
* @author Erwin Bolwidt <ejb@klomp.org>
*/
final class CastExpr extends Expression {
private final Expression _left;
/**
* Legal conversions between internal types.
*/
static private MultiHashtable InternalTypeMap = new MultiHashtable();
static {
// Possible type conversions between internal types
InternalTypeMap.put(Type.Boolean, Type.Boolean);
InternalTypeMap.put(Type.Boolean, Type.Real);
InternalTypeMap.put(Type.Boolean, Type.String);
InternalTypeMap.put(Type.Boolean, Type.Reference);
InternalTypeMap.put(Type.Boolean, Type.Object);
InternalTypeMap.put(Type.Real, Type.Real);
InternalTypeMap.put(Type.Real, Type.Int);
InternalTypeMap.put(Type.Real, Type.Boolean);
InternalTypeMap.put(Type.Real, Type.String);
InternalTypeMap.put(Type.Real, Type.Reference);
InternalTypeMap.put(Type.Real, Type.Object);
InternalTypeMap.put(Type.Int, Type.Int);
InternalTypeMap.put(Type.Int, Type.Real);
InternalTypeMap.put(Type.Int, Type.Boolean);
InternalTypeMap.put(Type.Int, Type.String);
InternalTypeMap.put(Type.Int, Type.Reference);
InternalTypeMap.put(Type.Int, Type.Object);
InternalTypeMap.put(Type.String, Type.String);
InternalTypeMap.put(Type.String, Type.Boolean);
InternalTypeMap.put(Type.String, Type.Real);
InternalTypeMap.put(Type.String, Type.Reference);
InternalTypeMap.put(Type.String, Type.Object);
InternalTypeMap.put(Type.NodeSet, Type.NodeSet);
InternalTypeMap.put(Type.NodeSet, Type.Boolean);
InternalTypeMap.put(Type.NodeSet, Type.Real);
InternalTypeMap.put(Type.NodeSet, Type.String);
InternalTypeMap.put(Type.NodeSet, Type.Node);
InternalTypeMap.put(Type.NodeSet, Type.Reference);
InternalTypeMap.put(Type.NodeSet, Type.Object);
InternalTypeMap.put(Type.Node, Type.Node);
InternalTypeMap.put(Type.Node, Type.Boolean);
InternalTypeMap.put(Type.Node, Type.Real);
InternalTypeMap.put(Type.Node, Type.String);
InternalTypeMap.put(Type.Node, Type.NodeSet);
InternalTypeMap.put(Type.Node, Type.Reference);
InternalTypeMap.put(Type.Node, Type.Object);
InternalTypeMap.put(Type.ResultTree, Type.ResultTree);
InternalTypeMap.put(Type.ResultTree, Type.Boolean);
InternalTypeMap.put(Type.ResultTree, Type.Real);
InternalTypeMap.put(Type.ResultTree, Type.String);
InternalTypeMap.put(Type.ResultTree, Type.NodeSet);
InternalTypeMap.put(Type.ResultTree, Type.Reference);
InternalTypeMap.put(Type.ResultTree, Type.Object);
InternalTypeMap.put(Type.Reference, Type.Reference);
InternalTypeMap.put(Type.Reference, Type.Boolean);
InternalTypeMap.put(Type.Reference, Type.Int);
InternalTypeMap.put(Type.Reference, Type.Real);
InternalTypeMap.put(Type.Reference, Type.String);
InternalTypeMap.put(Type.Reference, Type.Node);
InternalTypeMap.put(Type.Reference, Type.NodeSet);
InternalTypeMap.put(Type.Reference, Type.ResultTree);
InternalTypeMap.put(Type.Reference, Type.Object);
InternalTypeMap.put(Type.Object, Type.String);
InternalTypeMap.put(Type.Void, Type.String);
}
private boolean _typeTest = false;
/**
* Construct a cast expression and check that the conversion is
* valid by calling typeCheck().
*/
public CastExpr(Expression left, Type type) throws TypeCheckError {
_left = left;
_type = type; // use inherited field
if ((_left instanceof Step) && (_type == Type.Boolean)) {
Step step = (Step)_left;
if ((step.getAxis() == Axis.SELF) && (step.getNodeType() != -1))
_typeTest = true;
}
// check if conversion is valid
setParser(left.getParser());
setParent(left.getParent());
left.setParent(this);
typeCheck(left.getParser().getSymbolTable());
}
public Expression getExpr() {
return _left;
}
/**
* Returns true if this expressions contains a call to position(). This is
* needed for context changes in node steps containing multiple predicates.
*/
public boolean hasPositionCall() {
return(_left.hasPositionCall());
}
public boolean hasLastCall() {
return(_left.hasLastCall());
}
public String toString() {
return "cast(" + _left + ", " + _type + ")";
}
/**
* Type checking a cast expression amounts to verifying that the
* type conversion is legal. Cast expressions are created during
* type checking, but typeCheck() is usually not called on them.
* As a result, this method is called from the constructor.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
Type tleft = _left.getType();
if (tleft == null) {
tleft = _left.typeCheck(stable);
}
if (tleft instanceof NodeType) {
tleft = Type.Node; // multiple instances
}
else if (tleft instanceof ResultTreeType) {
tleft = Type.ResultTree; // multiple instances
}
if (InternalTypeMap.maps(tleft, _type) != null) {
return _type;
}
// throw new TypeCheckError(this);
throw new TypeCheckError(new ErrorMsg(
ErrorMsg.DATA_CONVERSION_ERR, tleft.toString(), _type.toString()));
}
public void translateDesynthesized(ClassGenerator classGen,
MethodGenerator methodGen) {
FlowList fl;
final Type ltype = _left.getType();
// This is a special case for the self:: axis. Instead of letting
// the Step object create and iterator that we cast back to a single
// node, we simply ask the DOM for the node type.
if (_typeTest) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
final int idx = cpg.addInterfaceMethodref(DOM_INTF,
"getExpandedTypeID",
"(I)I");
il.append(new SIPUSH((short)((Step)_left).getNodeType()));
il.append(methodGen.loadDOM());
il.append(methodGen.loadContextNode());
il.append(new INVOKEINTERFACE(idx, 2));
_falseList.add(il.append(new IF_ICMPNE(null)));
}
else {
_left.translate(classGen, methodGen);
if (_type != ltype) {
_left.startIterator(classGen, methodGen);
if (_type instanceof BooleanType) {
fl = ltype.translateToDesynthesized(classGen, methodGen,
_type);
if (fl != null) {
_falseList.append(fl);
}
}
else {
ltype.translateTo(classGen, methodGen, _type);
}
}
}
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final Type ltype = _left.getType();
_left.translate(classGen, methodGen);
if (_type.identicalTo(ltype) == false) {
_left.startIterator(classGen, methodGen);
ltype.translateTo(classGen, methodGen, _type);
}
}
}