| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| /* |
| * 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. |
| */ |
| package com.sun.org.apache.bcel.internal.generic; |
| |
| /** |
| * 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 |
| */ |
| public final class BranchHandle extends InstructionHandle { |
| |
| // This is also a cache in case the InstructionHandle#swapInstruction() method is used |
| // See BCEL-273 |
| private BranchInstruction bi; // An alias in fact, but saves lots of casts |
| |
| |
| private BranchHandle(final BranchInstruction i) { |
| super(i); |
| bi = i; |
| } |
| |
| /** Factory method. |
| */ |
| static BranchHandle getBranchHandle( final BranchInstruction i ) { |
| return new BranchHandle(i); |
| } |
| |
| |
| /* Override InstructionHandle methods: delegate to branch instruction. |
| * Through this overriding all access to the private i_position field should |
| * be prevented. |
| */ |
| @Override |
| public int getPosition() { |
| return bi.getPosition(); |
| } |
| |
| |
| @Override |
| void setPosition( final int pos ) { |
| // Original code: i_position = bi.position = pos; |
| bi.setPosition(pos); |
| super.setPosition(pos); |
| } |
| |
| |
| @Override |
| protected int updatePosition( final int offset, final int max_offset ) { |
| final int x = bi.updatePosition(offset, max_offset); |
| super.setPosition(bi.getPosition()); |
| return x; |
| } |
| |
| |
| /** |
| * Pass new target to instruction. |
| */ |
| public void setTarget( final InstructionHandle ih ) { |
| bi.setTarget(ih); |
| } |
| |
| |
| /** |
| * Update target of instruction. |
| */ |
| public void updateTarget( final InstructionHandle old_ih, final 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. |
| */ |
| @Override // This is only done in order to apply the additional type check; could be merged with super impl. |
| public void setInstruction( final Instruction i ) { // TODO could be package-protected? |
| super.setInstruction(i); |
| if (!(i instanceof BranchInstruction)) { |
| throw new ClassGenException("Assigning " + i |
| + " to branch handle which is not a branch instruction"); |
| } |
| bi = (BranchInstruction) i; |
| } |
| } |