/*
* @(#)$Id$
*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001 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 java.util.Vector;
import org.apache.xalan.xsltc.compiler.util.Type;
import de.fub.bytecode.generic.*;
import org.apache.xalan.xsltc.compiler.util.*;
import org.apache.xalan.xsltc.dom.Axis;
import org.apache.xalan.xsltc.DOM;
final class Step extends RelativeLocationPath {
// This step's axis as defined in class Axis.
private int _axis;
// A vector of predicates (filters) defined on this step.
private final Vector _predicates; // may be null
// Type of the node test.
private final int _nodeType;
private boolean _hadPredicates = false;
/**
* Constructor
*/
public Step(int axis, int nodeType, Vector predicates) {
_axis = axis;
_nodeType = nodeType;
_predicates = predicates;
}
/**
* Set the parser for this element and all child predicates
*/
public void setParser(Parser parser) {
super.setParser(parser);
if (_predicates != null) {
final int n = _predicates.size();
for (int i = 0; i < n; i++) {
final Predicate exp = (Predicate)_predicates.elementAt(i);
exp.setParser(parser);
exp.setParent(this);
}
}
}
/**
* Define the axis (defined in Axis class) for this step
*/
public int getAxis() {
return _axis;
}
/**
* Get the axis (defined in Axis class) for this step
*/
public void setAxis(int axis) {
_axis = axis;
}
public boolean descendantAxis() {
if ((_axis == Axis.DESCENDANT) || (_axis == Axis.DESCENDANTORSELF))
return(true);
else
return(false);
}
public boolean isSelf() {
return (_axis == Axis.SELF);
}
/**
* Returns the node-type for this step
*/
public int getNodeType() {
return _nodeType;
}
/**
* Returns the vector containing all predicates for this step.
*/
public Vector getPredicates() {
return _predicates;
}
/**
* Returns 'true' if this step has a parent pattern
*/
public boolean hasParent() {
SyntaxTreeNode parent = getParent();
if ((parent instanceof ParentPattern) ||
(parent instanceof ParentLocationPath) ||
(parent instanceof FilterParentPath))
return(true);
else
return(false);
}
/**
* Returns 'true' if this step has any predicates
*/
public boolean hasPredicates() {
return _predicates != null && _predicates.size() > 0;
}
/**
* True if this step is the abbreviated step '.'
*/
public boolean isAbbreviatedDot() {
return _nodeType == NodeTest.ANODE && _axis == Axis.SELF;
}
/**
* True if this step is the abbreviated step '..'
*/
public boolean isAbbreviatedDDot() {
return _nodeType == NodeTest.ANODE && _axis == Axis.PARENT;
}
/**
* Type check this step. The abbreviated steps '.' and '@attr' are
* assigned type node if they have no predicates. All other steps
* have type node-set.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
_hadPredicates = hasPredicates();
if (isAbbreviatedDot()) {
_type = Type.Node;
}
else if (isAbbreviatedDDot()) {
_type = Type.NodeSet;
}
else {
// Special case for '@attr' with no parent or predicates
if (_axis == Axis.ATTRIBUTE
&& _nodeType != NodeTest.ATTRIBUTE
&& !hasParent()
&& !hasPredicates()) {
_type = Type.Node;
}
else {
_type = Type.NodeSet;
}
}
if (_predicates != null) {
final int n = _predicates.size();
for (int i = 0; i < n; i++) {
final Expression pred = (Expression)_predicates.elementAt(i);
pred.typeCheck(stable);
}
}
return _type;
}
/**
* Translate a step by pushing the appropriate iterator onto the stack.
* The abbreviated steps '.' and '@attr' do not create new iterators
* if they are not part of a LocationPath and have no filters.
* In these cases a node index instead of an iterator is pushed
* onto the stack.
*/
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
final String DOM_CLASS = classGen.getDOMClass();
if (hasPredicates()) {
translatePredicates(classGen, methodGen);
}
else {
// If it is an attribute but not '@*' or '@attr' with a parent
if ((_axis == Axis.ATTRIBUTE) &&
(_nodeType != NodeTest.ATTRIBUTE) && (!hasParent())) {
final int gattr = cpg.addMethodref(DOM_CLASS,
"getAttributeNode",
"(II)I");
il.append(methodGen.loadDOM());
il.append(new PUSH(cpg, _nodeType));
il.append(methodGen.loadContextNode());
il.append(new INVOKEVIRTUAL(gattr));
// If it is the case '@attr[P_1]...[P_k]'
if (_type instanceof NodeSetType) {
Type.Node.translateTo(classGen, methodGen, _type);
}
return;
}
// Special case for '.'
if (_type == Type.Node) {
il.append(methodGen.loadContextNode());
return;
}
// "ELEMENT" or "*" or "@*" or ".." or "@attr" with a parent.
switch (_nodeType) {
case NodeTest.ATTRIBUTE:
_axis = Axis.ATTRIBUTE;
case NodeTest.ANODE:
// DOM.getAxisIterator(int axis);
final int it = cpg.addMethodref(DOM_CLASS,
"getAxisIterator",
"(I)"+NODE_ITERATOR_SIG);
il.append(methodGen.loadDOM());
il.append(new PUSH(cpg, _axis));
il.append(new INVOKEVIRTUAL(it));
break;
default:
final XSLTC xsltc = getParser().getXSLTC();
final Vector ni = xsltc.getNamesIndex();
String name = null;
int star = 0;
if (_nodeType >= DOM.NTYPES) {
name = (String)ni.elementAt(_nodeType-DOM.NTYPES);
star = name.lastIndexOf('*');
}
if (star > 1) {
final String namespace;
if (_axis == Axis.ATTRIBUTE)
namespace = name.substring(0,star-2);
else
namespace = name.substring(0,star-1);
final int nsType = xsltc.registerNamespace(namespace);
final int ns = cpg.addMethodref(DOM_CLASS,
"getNamespaceAxisIterator",
"(II)"+NODE_ITERATOR_SIG);
il.append(methodGen.loadDOM());
il.append(new PUSH(cpg, _axis));
il.append(new PUSH(cpg, nsType));
il.append(new INVOKEVIRTUAL(ns));
break;
}
case NodeTest.ELEMENT:
// DOM.getTypedAxisIterator(int axis, int type);
final int ty = cpg.addMethodref(DOM_CLASS,
"getTypedAxisIterator",
"(II)"+NODE_ITERATOR_SIG);
// Get the typed iterator we're after
il.append(methodGen.loadDOM());
il.append(new PUSH(cpg, _axis));
il.append(new PUSH(cpg, _nodeType));
il.append(new INVOKEVIRTUAL(ty));
// Now, for reverse iterators we may need to re-arrange the
// node ordering (ancestor-type iterators).
if (!(getParent() instanceof ForEach)) {
if ((!hasParent()) && (!_hadPredicates))
orderIterator(classGen, methodGen);
}
break;
}
}
}
/**
* Translate a sequence of predicates. Each predicate is translated
* by constructing an instance of <code>CurrentNodeListIterator</code>
* which is initialized from another iterator (recursive call),
* a filter and a closure (call to translate on the predicate) and "this".
*/
public void translatePredicates(ClassGenerator classGen,
MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
final String DOM_CLASS = classGen.getDOMClass();
if (_predicates.size() == 0) {
translate(classGen, methodGen);
}
else {
final Predicate predicate = (Predicate)_predicates.lastElement();
_predicates.remove(predicate);
// Handle '//*[n]' expression
if (predicate.isNthDescendant()) {
il.append(methodGen.loadDOM());
il.append(methodGen.loadContextNode());
predicate.translate(classGen, methodGen);
final int nth = cpg.addMethodref(DOM_CLASS,
"getNthDescendant",
"(II)"+NODE_ITERATOR_SIG);
il.append(new INVOKEVIRTUAL(nth));
}
// Handle 'elem[n]' expression
else if (predicate.isNthPositionFilter()) {
final int initNI =
cpg.addMethodref(NTH_ITERATOR_CLASS,
"<init>",
"(" + NODE_ITERATOR_SIG + "I)V");
il.append(new NEW(cpg.addClass(NTH_ITERATOR_CLASS)));
il.append(DUP);
translatePredicates(classGen, methodGen); // recursive call
predicate.translate(classGen, methodGen);
il.append(new INVOKESPECIAL(initNI));
}
else {
final int initCNLI =
cpg.addMethodref(CURRENT_NODE_LIST_ITERATOR,
"<init>",
"("
+ NODE_ITERATOR_SIG
+ CURRENT_NODE_LIST_FILTER_SIG
+ NODE_SIG // current node
+ TRANSLET_SIG
+ ")V");
// create new CurrentNodeListIterator
il.append(new NEW(cpg.addClass(CURRENT_NODE_LIST_ITERATOR)));
il.append(DUP);
translatePredicates(classGen, methodGen); // recursive call
predicate.translate(classGen, methodGen);
il.append(methodGen.loadCurrentNode());
il.append(classGen.loadTranslet());
il.append(new INVOKESPECIAL(initCNLI));
}
}
}
/*
* Order nodes for iterators with reverse axis
*
* Should be done for preceding and preceding-sibling axis as well,
* but our iterators for those axis are not reverse (as they should)
*/
public void orderIterator(ClassGenerator classGen,
MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
if ((_axis == Axis.ANCESTOR) || (_axis == Axis.ANCESTORORSELF)) {
final int init = cpg.addMethodref(REVERSE_ITERATOR, "<init>",
"("+NODE_ITERATOR_SIG+")V");
il.append(new NEW(cpg.addClass(REVERSE_ITERATOR)));
il.append(DUP_X1);
il.append(SWAP);
il.append(new INVOKESPECIAL(init));
}
}
/**
* Returns a string representation of this step.
*/
public String toString() {
final StringBuffer buffer = new StringBuffer("step(\"");
buffer.append(Axis.names[_axis]).append("\", ").append(_nodeType);
if (_predicates != null) {
final int n = _predicates.size();
for (int i = 0; i < n; i++) {
final Predicate pred = (Predicate)_predicates.elementAt(i);
buffer.append(", ").append(pred.toString());
}
}
return buffer.append(')').toString();
}
}