com.sun.org.apache.xalan.internal.xsltc.compiler.AncestorPattern Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
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: AncestorPattern.java,v 1.10 2010-11-01 04:34:15 joehw Exp $
 */
package com.sun.org.apache.xalan.internal.xsltc.compiler;

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.IFLT;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.ISTORE;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
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 Erwin Bolwidt 
 */
final class AncestorPattern extends RelativePathPattern {

    private final Pattern _left;	// may be null
    private final RelativePathPattern _right;
    private InstructionHandle _loop;
		
    public AncestorPattern(RelativePathPattern right) {
	this(null, right);
    }

    public AncestorPattern(Pattern left, RelativePathPattern right) {
	_left = left;
	(_right = right).setParent(this);
	if (left != null) {
	    left.setParent(this);
	}
    }
	
    public InstructionHandle getLoopHandle() {
	return _loop;
    }

    public void setParser(Parser parser) {
	super.setParser(parser);
	if (_left != null) {
	    _left.setParser(parser);
	}
	_right.setParser(parser);
    }
    
    public boolean isWildcard() {
	//!!! can be wildcard
	return false;
    }
	
    public StepPattern getKernelPattern() {
	return _right.getKernelPattern();
    }

    public void reduceKernelPattern() {
	_right.reduceKernelPattern();
    }
	
    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	if (_left != null) {
	    _left.typeCheck(stable);
	}
	return _right.typeCheck(stable);
    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	InstructionHandle parent;
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	/* 
	 * The scope of this local var must be the entire method since
	 * a another pattern may decide to jump back into the loop
	 */
	final LocalVariableGen local =
	    methodGen.addLocalVariable2("app", Util.getJCRefType(NODE_SIG),
					il.getEnd());

	final com.sun.org.apache.bcel.internal.generic.Instruction loadLocal =
	    new ILOAD(local.getIndex());
	final com.sun.org.apache.bcel.internal.generic.Instruction storeLocal =
	    new ISTORE(local.getIndex());

	if (_right instanceof StepPattern) {
	    il.append(DUP);
	    il.append(storeLocal);
	    _right.translate(classGen, methodGen);
	    il.append(methodGen.loadDOM());
	    il.append(loadLocal);
	}
	else {
	    _right.translate(classGen, methodGen);

	    if (_right instanceof AncestorPattern) {
		il.append(methodGen.loadDOM());
		il.append(SWAP);
	    }
	}

	if (_left != null) {
	    final int getParent = cpg.addInterfaceMethodref(DOM_INTF,
							    GET_PARENT,
							    GET_PARENT_SIG);
	    parent = il.append(new INVOKEINTERFACE(getParent, 2));
	    
	    il.append(DUP);
	    il.append(storeLocal);
	    _falseList.add(il.append(new IFLT(null)));
	    il.append(loadLocal);

	    _left.translate(classGen, methodGen);

	    final SyntaxTreeNode p = getParent();
	    if (p == null || p instanceof Instruction ||
		p instanceof TopLevelElement) 
	    {
		// do nothing
	    }
	    else {
		il.append(loadLocal);
	    }

	    final BranchHandle exit = il.append(new GOTO(null));
	    _loop = il.append(methodGen.loadDOM());
	    il.append(loadLocal);
	    local.setEnd(_loop);
	    il.append(new GOTO(parent));
	    exit.setTarget(il.append(NOP));
	    _left.backPatchFalseList(_loop);

	    _trueList.append(_left._trueList);	
	}
	else {
	    il.append(POP2);
	}
	
	/* 
	 * If _right is an ancestor pattern, backpatch this pattern's false
	 * list to the loop that searches for more ancestors.
	 */
	if (_right instanceof AncestorPattern) {
	    final AncestorPattern ancestor = (AncestorPattern) _right;
	    _falseList.backPatch(ancestor.getLoopHandle());    // clears list
	}

	_trueList.append(_right._trueList);
	_falseList.append(_right._falseList);
    }

    public String toString() {
	return "AncestorPattern(" + _left + ", " + _right + ')';
    }
}