| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| |
| package org.apache.xalan.xsltc.compiler; |
| |
| import java.util.Iterator; |
| import java.util.Vector; |
| |
| import org.apache.bcel.generic.BranchHandle; |
| import org.apache.bcel.generic.InstructionHandle; |
| import org.apache.bcel.generic.InstructionList; |
| |
| /** |
| * @author Jacek Ambroziak |
| * @author Santiago Pericas-Geertsen |
| */ |
| public final class FlowList { |
| private Vector _elements; |
| |
| public FlowList() { |
| _elements = null; |
| } |
| |
| public FlowList(InstructionHandle bh) { |
| _elements = new Vector(); |
| _elements.addElement(bh); |
| } |
| |
| public FlowList(FlowList list) { |
| _elements = list._elements; |
| } |
| |
| public FlowList add(InstructionHandle bh) { |
| if (_elements == null) { |
| _elements = new Vector(); |
| } |
| _elements.addElement(bh); |
| return this; |
| } |
| |
| public FlowList append(FlowList right) { |
| if (_elements == null) { |
| _elements = right._elements; |
| } |
| else { |
| final Vector temp = right._elements; |
| if (temp != null) { |
| final int n = temp.size(); |
| for (int i = 0; i < n; i++) { |
| _elements.addElement(temp.elementAt(i)); |
| } |
| } |
| } |
| return this; |
| } |
| |
| /** |
| * Back patch a flow list. All instruction handles must be branch handles. |
| */ |
| public void backPatch(InstructionHandle target) { |
| if (_elements != null) { |
| final int n = _elements.size(); |
| for (int i = 0; i < n; i++) { |
| BranchHandle bh = (BranchHandle)_elements.elementAt(i); |
| bh.setTarget(target); |
| } |
| _elements.clear(); // avoid backpatching more than once |
| } |
| } |
| |
| /** |
| * Redirect the handles from oldList to newList. "This" flow list |
| * is assumed to be relative to oldList. |
| */ |
| public FlowList copyAndRedirect(InstructionList oldList, |
| InstructionList newList) |
| { |
| final FlowList result = new FlowList(); |
| if (_elements == null) { |
| return result; |
| } |
| |
| final int n = _elements.size(); |
| final Iterator oldIter = oldList.iterator(); |
| final Iterator newIter = newList.iterator(); |
| |
| while (oldIter.hasNext()) { |
| final InstructionHandle oldIh = (InstructionHandle) oldIter.next(); |
| final InstructionHandle newIh = (InstructionHandle) newIter.next(); |
| |
| for (int i = 0; i < n; i++) { |
| if (_elements.elementAt(i) == oldIh) { |
| result.add(newIh); |
| } |
| } |
| } |
| return result; |
| } |
| } |