com.sun.org.apache.xalan.internal.xsltc.compiler.ForEach Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jaxp-ri Show documentation
Show all versions of jaxp-ri Show documentation
Java API for XML Processing Reference Implementation
The newest version!
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* 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: ForEach.java,v 1.10 2010-11-01 04:34:16 joehw Exp $
*/
package com.sun.org.apache.xalan.internal.xsltc.compiler;
import java.util.Enumeration;
import java.util.Vector;
import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GOTO;
import com.sun.org.apache.bcel.internal.generic.IFGT;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSetType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ReferenceType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
/**
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
* @author Morten Jorgensen
*/
final class ForEach extends Instruction {
private Expression _select;
private Type _type;
public void display(int indent) {
indent(indent);
Util.println("ForEach");
indent(indent + IndentIncrement);
Util.println("select " + _select.toString());
displayContents(indent + IndentIncrement);
}
public void parseContents(Parser parser) {
_select = parser.parseExpression(this, "select", null);
parseChildren(parser);
// make sure required attribute(s) have been set
if (_select.isDummy()) {
reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "select");
}
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
_type = _select.typeCheck(stable);
if (_type instanceof ReferenceType || _type instanceof NodeType) {
_select = new CastExpr(_select, Type.NodeSet);
typeCheckContents(stable);
return Type.Void;
}
if (_type instanceof NodeSetType||_type instanceof ResultTreeType) {
typeCheckContents(stable);
return Type.Void;
}
throw new TypeCheckError(this);
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Save current node and current iterator on the stack
il.append(methodGen.loadCurrentNode());
il.append(methodGen.loadIterator());
// Collect sort objects associated with this instruction
final Vector sortObjects = new Vector();
Enumeration children = elements();
while (children.hasMoreElements()) {
final Object child = children.nextElement();
if (child instanceof Sort) {
sortObjects.addElement(child);
}
}
if ((_type != null) && (_type instanceof ResultTreeType)) {
// Store existing DOM on stack - must be restored when loop is done
il.append(methodGen.loadDOM());
// cannot be applied to a result tree - issue warning
if (sortObjects.size() > 0) {
ErrorMsg msg = new ErrorMsg(ErrorMsg.RESULT_TREE_SORT_ERR,this);
getParser().reportError(WARNING, msg);
}
// Put the result tree on the stack (DOM)
_select.translate(classGen, methodGen);
// Get an iterator for the whole DOM - excluding the root node
_type.translateTo(classGen, methodGen, Type.NodeSet);
// Store the result tree as the default DOM
il.append(SWAP);
il.append(methodGen.storeDOM());
}
else {
// Compile node iterator
if (sortObjects.size() > 0) {
Sort.translateSortIterator(classGen, methodGen,
_select, sortObjects);
}
else {
_select.translate(classGen, methodGen);
}
if (_type instanceof ReferenceType == false) {
il.append(methodGen.loadContextNode());
il.append(methodGen.setStartNode());
}
}
// Overwrite current iterator
il.append(methodGen.storeIterator());
// Give local variables (if any) default values before starting loop
initializeVariables(classGen, methodGen);
final BranchHandle nextNode = il.append(new GOTO(null));
final InstructionHandle loop = il.append(NOP);
translateContents(classGen, methodGen);
nextNode.setTarget(il.append(methodGen.loadIterator()));
il.append(methodGen.nextNode());
il.append(DUP);
il.append(methodGen.storeCurrentNode());
il.append(new IFGT(loop));
// Restore current DOM (if result tree was used instead for this loop)
if ((_type != null) && (_type instanceof ResultTreeType)) {
il.append(methodGen.storeDOM());
}
// Restore current node and current iterator from the stack
il.append(methodGen.storeIterator());
il.append(methodGen.storeCurrentNode());
}
/**
* The code that is generated by nested for-each loops can appear to some
* JVMs as if it is accessing un-initialized variables. We must add some
* code that pushes the default variable value on the stack and pops it
* into the variable slot. This is done by the Variable.initialize()
* method. The code that we compile for this loop looks like this:
*
* initialize iterator
* initialize variables <-- HERE!!!
* goto Iterate
* Loop: :
* : (code for contents)
* :
* Iterate: node = iterator.next();
* if (node != END) goto Loop
*/
public void initializeVariables(ClassGenerator classGen,
MethodGenerator methodGen) {
final int n = elementCount();
for (int i = 0; i < n; i++) {
final Object child = getContents().elementAt(i);
if (child instanceof Variable) {
Variable var = (Variable)child;
var.initialize(classGen, methodGen);
}
}
}
}