/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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: AbsoluteLocationPath.java 468650 2006-10-28 07:03:30Z minchau $
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.bcel.generic.ALOAD;
import org.apache.bcel.generic.ASTORE;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.INVOKESPECIAL;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.LocalVariableGen;
import org.apache.bcel.generic.NEW;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.NodeType;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
import org.apache.xalan.xsltc.compiler.util.Util;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*/
final class AbsoluteLocationPath extends Expression {
private Expression _path; // may be null
public AbsoluteLocationPath() {
_path = null;
}
public AbsoluteLocationPath(Expression path) {
_path = path;
if (path != null) {
_path.setParent(this);
}
}
public void setParser(Parser parser) {
super.setParser(parser);
if (_path != null) {
_path.setParser(parser);
}
}
public Expression getPath() {
return(_path);
}
public String toString() {
return "AbsoluteLocationPath(" +
(_path != null ? _path.toString() : "null") + ')';
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
if (_path != null) {
final Type ptype = _path.typeCheck(stable);
if (ptype instanceof NodeType) { // promote to node-set
_path = new CastExpr(_path, Type.NodeSet);
}
}
return _type = Type.NodeSet;
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
if (_path != null) {
final int initAI = cpg.addMethodref(ABSOLUTE_ITERATOR,
"<init>",
"("
+ NODE_ITERATOR_SIG
+ ")V");
// Compile relative path iterator(s)
//
// Backwards branches are prohibited if an uninitialized object is
// on the stack by section 4.9.4 of the JVM Specification, 2nd Ed.
// We don't know whether this code might contain backwards branches,
// so we mustn't create the new object until after we've created
// this argument to its constructor. Instead we calculate the
// value of the argument to the constructor first, store it in
// a temporary variable, create the object and reload the argument
// from the temporary to avoid the problem.
_path.translate(classGen, methodGen);
LocalVariableGen relPathIterator
= methodGen.addLocalVariable("abs_location_path_tmp",
Util.getJCRefType(NODE_ITERATOR_SIG),
null, null);
relPathIterator.setStart(
il.append(new ASTORE(relPathIterator.getIndex())));
// Create new AbsoluteIterator
il.append(new NEW(cpg.addClass(ABSOLUTE_ITERATOR)));
il.append(DUP);
relPathIterator.setEnd(
il.append(new ALOAD(relPathIterator.getIndex())));
// Initialize AbsoluteIterator with iterator from the stack
il.append(new INVOKESPECIAL(initAI));
}
else {
final int gitr = cpg.addInterfaceMethodref(DOM_INTF,
"getIterator",
"()"+NODE_ITERATOR_SIG);
il.append(methodGen.loadDOM());
il.append(new INVOKEINTERFACE(gitr, 1));
}
}
}