/*
* @(#)$Id$
*
* 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 java.util.Hashtable;
import java.util.Dictionary;
import java.util.Enumeration;
import de.fub.bytecode.generic.*;
import org.apache.xalan.xsltc.compiler.util.*;
final class TestSeq {
private Vector _patterns;
private final Mode _mode;
// template to instantiate when all (reduced) tests fail
// and the sequence is not extended
// when the _template is null, control should go to 'NextNode'
private Template _template = null;
private InstructionList _instructionList;
public TestSeq(Vector patterns, Mode mode) {
_patterns = patterns;
_mode = mode;
}
public double getPriority() {
if (_template == null)
return(Double.NaN);
else
return(_template.getPriority());
}
public int getPosition() {
if (_template == null)
return(0);
else
return(_template.getPosition());
}
// careful with test ordering
public void reduce() {
final int nPatterns = _patterns.size();
for (int i = 0; i < nPatterns; i++)
Util.println(_patterns.elementAt(i).toString());
final Vector newPatterns = new Vector();
for (int i = 0; i < nPatterns; i++) {
final LocationPathPattern pattern =
(LocationPathPattern)_patterns.elementAt(i);
pattern.reduceKernelPattern();
// we only retain nontrivial reduced patterns
// also, anything that could follow a trivial pattern
// can be omitted
if (!pattern.isWildcard()) {
newPatterns.addElement(pattern);
}
else {
// failure of the previous test falls through to this fully
// reduced test, succeeding by definition and branching
// unconditionally to the test's template
_template = pattern.getTemplate();
break;
}
}
_patterns = newPatterns;
//Util.println("patterns after reduction");
for (int i = 0; i < _patterns.size(); i++)
Util.println(_patterns.elementAt(i).toString());
}
public void findTemplates(Dictionary templates) {
if (_template != null)
templates.put(_template, this);
for (int i = 0; i < _patterns.size(); i++) {
final LocationPathPattern pattern =
(LocationPathPattern)_patterns.elementAt(i);
templates.put(pattern.getTemplate(), this);
}
}
private InstructionHandle getTemplateHandle(Template template) {
return (InstructionHandle)_mode.getTemplateInstructionHandle(template);
}
private LocationPathPattern getPattern(int n) {
return (LocationPathPattern)_patterns.elementAt(n);
}
public InstructionHandle compile(ClassGenerator classGen,
MethodGenerator methodGen,
InstructionHandle continuation) {
if (_patterns.size() == 0) {
//Util.println("compiling trivial testseq " + _template);
return getTemplateHandle(_template);
}
else {
// 'fail' represents a branch to go to when test fails
// it is updated in each iteration so that the tests
// are linked together in the
// if elseif elseif ... else fashion
InstructionHandle fail = _template == null
? continuation
: getTemplateHandle(_template);
for (int n = _patterns.size() - 1; n >= 0; n--) {
final LocationPathPattern pattern = getPattern(n);
final InstructionList il = new InstructionList();
// patterns expect current node on top of stack
il.append(methodGen.loadCurrentNode());
// apply the actual pattern
il.append(pattern.compile(classGen, methodGen));
// on success (fallthrough) goto template code
final InstructionHandle success =
il.append(new GOTO(getTemplateHandle(pattern.getTemplate())));
pattern.backPatchTrueList(success);
pattern.backPatchFalseList(fail);
// the failure of the preceding test will lead to this test
fail = il.getStart();
if (_instructionList != null) {
il.append(_instructionList);
}
_instructionList = il;
}
return fail;
}
}
public InstructionList getInstructionList() {
return _instructionList;
}
}