/*
* @(#)$Id: ParentLocationPath.java,v 1.21 2003/01/30 18:46:01 mkwan Exp $
*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 2001, Sun
* Microsystems., http://www.sun.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* @author Jacek Ambroziak
* @author Santiago Pericas-Geertsen
*
*/
package org.apache.xalan.xsltc.compiler;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.INVOKESPECIAL;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.NEW;
import org.apache.xalan.xsltc.DOM;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
import org.apache.xalan.xsltc.dom.Axis;
final class ParentLocationPath extends RelativeLocationPath {
private Expression _step;
private final RelativeLocationPath _path;
private Type stype;
private boolean _orderNodes = false;
private boolean _axisMismatch = false;
public ParentLocationPath(RelativeLocationPath path, Expression step) {
_path = path;
_step = step;
_path.setParent(this);
_step.setParent(this);
if (_step instanceof Step) {
_axisMismatch = checkAxisMismatch();
}
}
public void setAxis(int axis) {
_path.setAxis(axis);
}
public int getAxis() {
return _path.getAxis();
}
public RelativeLocationPath getPath() {
return(_path);
}
public Expression getStep() {
return(_step);
}
public void setParser(Parser parser) {
super.setParser(parser);
_step.setParser(parser);
_path.setParser(parser);
}
public String toString() {
return "ParentLocationPath(" + _path + ", " + _step + ')';
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
stype = _step.typeCheck(stable);
_path.typeCheck(stable);
if (_axisMismatch) enableNodeOrdering();
return _type = Type.NodeSet;
}
public void enableNodeOrdering() {
SyntaxTreeNode parent = getParent();
if (parent instanceof ParentLocationPath)
((ParentLocationPath)parent).enableNodeOrdering();
else {
_orderNodes = true;
}
}
/**
* This method is used to determine if this parent location path is a
* combination of two step's with axes that will create duplicate or
* unordered nodes.
*/
public boolean checkAxisMismatch() {
int left = _path.getAxis();
int right = ((Step)_step).getAxis();
if (((left == Axis.ANCESTOR) || (left == Axis.ANCESTORORSELF)) &&
((right == Axis.CHILD) ||
(right == Axis.DESCENDANT) ||
(right == Axis.DESCENDANTORSELF) ||
(right == Axis.PARENT) ||
(right == Axis.PRECEDING) ||
(right == Axis.PRECEDINGSIBLING)))
return true;
if ((left == Axis.CHILD) &&
(right == Axis.ANCESTOR) ||
(right == Axis.ANCESTORORSELF) ||
(right == Axis.PARENT) ||
(right == Axis.PRECEDING))
return true;
if ((left == Axis.DESCENDANT) || (left == Axis.DESCENDANTORSELF))
return true;
if (((left == Axis.FOLLOWING) || (left == Axis.FOLLOWINGSIBLING)) &&
((right == Axis.FOLLOWING) ||
(right == Axis.PARENT) ||
(right == Axis.PRECEDING) ||
(right == Axis.PRECEDINGSIBLING)))
return true;
if (((left == Axis.PRECEDING) || (left == Axis.PRECEDINGSIBLING)) &&
((right == Axis.DESCENDANT) ||
(right == Axis.DESCENDANTORSELF) ||
(right == Axis.FOLLOWING) ||
(right == Axis.FOLLOWINGSIBLING) ||
(right == Axis.PARENT) ||
(right == Axis.PRECEDING) ||
(right == Axis.PRECEDINGSIBLING)))
return true;
if ((right == Axis.FOLLOWING) && (left == Axis.CHILD)) {
// Special case for '@*/following::*' expressions. The resulting
// iterator is initialised with the parent's first child, and this
// can cause duplicates in the output if the parent has more than
// one attribute that matches the left step.
if (_path instanceof Step) {
int type = ((Step)_path).getNodeType();
if (type == DOM.ATTRIBUTE) return true;
}
}
return false;
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
// Create new StepIterator
final int initSI = cpg.addMethodref(STEP_ITERATOR_CLASS,
"<init>",
"("
+NODE_ITERATOR_SIG
+NODE_ITERATOR_SIG
+")V");
il.append(new NEW(cpg.addClass(STEP_ITERATOR_CLASS)));
il.append(DUP);
// Compile path iterator
_path.translate(classGen, methodGen); // iterator on stack....
_step.translate(classGen, methodGen);
// Initialize StepIterator with iterators from the stack
il.append(new INVOKESPECIAL(initSI));
// This is a special case for the //* path with or without predicates
Expression stp = _step;
if (stp instanceof ParentLocationPath)
stp = ((ParentLocationPath)stp).getStep();
if ((_path instanceof Step) && (stp instanceof Step)) {
final int path = ((Step)_path).getAxis();
final int step = ((Step)stp).getAxis();
if ((path == Axis.DESCENDANTORSELF && step == Axis.CHILD) ||
(path == Axis.PRECEDING && step == Axis.PARENT)) {
final int incl = cpg.addMethodref(NODE_ITERATOR_BASE,
"includeSelf",
"()" + NODE_ITERATOR_SIG);
il.append(new INVOKEVIRTUAL(incl));
}
}
/*
* If this pattern contains a sequence of descendant iterators we
* run the risk of returning the same node several times. We put
* a new iterator on top of the existing one to assure node order
* and prevent returning a single node multiple times.
*/
if (_orderNodes) {
final int order = cpg.addInterfaceMethodref(DOM_INTF,
ORDER_ITERATOR,
ORDER_ITERATOR_SIG);
il.append(methodGen.loadDOM());
il.append(SWAP);
il.append(methodGen.loadContextNode());
il.append(new INVOKEINTERFACE(order, 3));
}
}
}