/*
* 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: FilterParentPath.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.INVOKEVIRTUAL;
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.NodeSetType;
import org.apache.xalan.xsltc.compiler.util.NodeType;
import org.apache.xalan.xsltc.compiler.util.ReferenceType;
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 FilterParentPath extends Expression {
private Expression _filterExpr;
private Expression _path;
private boolean _hasDescendantAxis = false;
public FilterParentPath(Expression filterExpr, Expression path) {
(_path = path).setParent(this);
(_filterExpr = filterExpr).setParent(this);
}
public void setParser(Parser parser) {
super.setParser(parser);
_filterExpr.setParser(parser);
_path.setParser(parser);
}
public String toString() {
return "FilterParentPath(" + _filterExpr + ", " + _path + ')';
}
public void setDescendantAxis() {
_hasDescendantAxis = true;
}
/**
* Type check a FilterParentPath. If the filter is not a node-set add a
* cast to node-set only if it is of reference type. This type coercion is
* needed for expressions like $x/LINE where $x is a parameter reference.
*/
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
final Type ftype = _filterExpr.typeCheck(stable);
if (ftype instanceof NodeSetType == false) {
if (ftype instanceof ReferenceType) {
_filterExpr = new CastExpr(_filterExpr, Type.NodeSet);
}
/*
else if (ftype instanceof ResultTreeType) {
_filterExpr = new CastExpr(_filterExpr, Type.NodeSet);
}
*/
else if (ftype instanceof NodeType) {
_filterExpr = new CastExpr(_filterExpr, Type.NodeSet);
}
else {
throw new TypeCheckError(this);
}
}
// Wrap single node path in a node set
final Type ptype = _path.typeCheck(stable);
if (!(ptype instanceof NodeSetType)) {
_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();
// Create new StepIterator
final int initSI = cpg.addMethodref(STEP_ITERATOR_CLASS,
"<init>",
"("
+NODE_ITERATOR_SIG
+NODE_ITERATOR_SIG
+")V");
// 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
// the suspect arguments to its constructor. Instead we calculate
// the values of the arguments to the constructor first, store them
// in temporary variables, create the object and reload the
// arguments from the temporaries to avoid the problem.
// Recursively compile 2 iterators
_filterExpr.translate(classGen, methodGen);
LocalVariableGen filterTemp =
methodGen.addLocalVariable("filter_parent_path_tmp1",
Util.getJCRefType(NODE_ITERATOR_SIG),
null, null);
filterTemp.setStart(il.append(new ASTORE(filterTemp.getIndex())));
_path.translate(classGen, methodGen);
LocalVariableGen pathTemp =
methodGen.addLocalVariable("filter_parent_path_tmp2",
Util.getJCRefType(NODE_ITERATOR_SIG),
null, null);
pathTemp.setStart(il.append(new ASTORE(pathTemp.getIndex())));
il.append(new NEW(cpg.addClass(STEP_ITERATOR_CLASS)));
il.append(DUP);
filterTemp.setEnd(il.append(new ALOAD(filterTemp.getIndex())));
pathTemp.setEnd(il.append(new ALOAD(pathTemp.getIndex())));
// Initialize StepIterator with iterators from the stack
il.append(new INVOKESPECIAL(initSI));
// This is a special case for the //* path with or without predicates
if (_hasDescendantAxis) {
final int incl = cpg.addMethodref(NODE_ITERATOR_BASE,
"includeSelf",
"()" + NODE_ITERATOR_SIG);
il.append(new INVOKEVIRTUAL(incl));
}
SyntaxTreeNode parent = getParent();
boolean parentAlreadyOrdered =
(parent instanceof RelativeLocationPath)
|| (parent instanceof FilterParentPath)
|| (parent instanceof KeyCall)
|| (parent instanceof CurrentCall)
|| (parent instanceof DocumentCall);
if (!parentAlreadyOrdered) {
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));
}
}
}