- package com.sun.org.apache.bcel.internal.generic;
-
- /* ====================================================================
- * 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 "Apache" and "Apache Software Foundation" and
- * "Apache BCEL" 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",
- * "Apache BCEL", 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. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- */
-
- /**
- * BranchHandle is returned by specialized InstructionList.append() whenever a
- * BranchInstruction is appended. This is useful when the target of this
- * instruction is not known at time of creation and must be set later
- * via setTarget().
- *
- * @see InstructionHandle
- * @see Instruction
- * @see InstructionList
- * @version $Id: BranchHandle.java,v 1.1.1.1 2001/10/29 20:00:06 jvanzyl Exp $
- * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
- */
- public final class BranchHandle extends InstructionHandle {
- private BranchInstruction bi; // An alias in fact, but saves lots of casts
-
- private BranchHandle(BranchInstruction i) {
- super(i);
- bi = i;
- }
-
- /** Factory methods.
- */
- private static BranchHandle bh_list = null; // List of reusable handles
-
- static final BranchHandle getBranchHandle(BranchInstruction i) {
- if(bh_list == null)
- return new BranchHandle(i);
- else {
- BranchHandle bh = bh_list;
- bh_list = (BranchHandle)bh.next;
-
- bh.setInstruction(i);
-
- return bh;
- }
- }
-
- /** Handle adds itself to the list of resuable handles.
- */
- protected void addHandle() {
- next = bh_list;
- bh_list = this;
- }
-
- /* Override InstructionHandle methods: delegate to branch instruction.
- * Through this overriding all access to the private i_position field should
- * be prevented.
- */
- public int getPosition() { return bi.position; }
-
- void setPosition(int pos) {
- i_position = bi.position = pos;
- }
-
- protected int updatePosition(int offset, int max_offset) {
- int x = bi.updatePosition(offset, max_offset);
- i_position = bi.position;
- return x;
- }
-
- /**
- * Pass new target to instruction.
- */
- public void setTarget(InstructionHandle ih) {
- bi.setTarget(ih);
- }
-
- /**
- * Update target of instruction.
- */
- public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
- bi.updateTarget(old_ih, new_ih);
- }
-
- /**
- * @return target of instruction.
- */
- public InstructionHandle getTarget() {
- return bi.getTarget();
- }
-
- /**
- * Set new contents. Old instruction is disposed and may not be used anymore.
- */
- public void setInstruction(Instruction i) {
- super.setInstruction(i);
-
- if(!(i instanceof BranchInstruction))
- throw new ClassGenException("Assigning " + i +
- " to branch handle which is not a branch instruction");
-
- bi = (BranchInstruction)i;
- }
- }
-