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Diffstat (limited to 'src/com/sun/org/apache/bcel/internal/generic/BranchInstruction.java')
| -rw-r--r-- | src/com/sun/org/apache/bcel/internal/generic/BranchInstruction.java | 269 |
1 files changed, 0 insertions, 269 deletions
diff --git a/src/com/sun/org/apache/bcel/internal/generic/BranchInstruction.java b/src/com/sun/org/apache/bcel/internal/generic/BranchInstruction.java deleted file mode 100644 index 36960f8..0000000 --- a/src/com/sun/org/apache/bcel/internal/generic/BranchInstruction.java +++ /dev/null @@ -1,269 +0,0 @@ -/* - * reserved comment block - * DO NOT REMOVE OR ALTER! - */ -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/>. - */ - -import java.io.*; -import com.sun.org.apache.bcel.internal.util.ByteSequence; - -/** - * Abstract super class for branching instructions like GOTO, IFEQ, etc.. - * Branch instructions may have a variable length, namely GOTO, JSR, - * LOOKUPSWITCH and TABLESWITCH. - * - * @see InstructionList - * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> - */ -public abstract class BranchInstruction extends Instruction implements InstructionTargeter { - protected int index; // Branch target relative to this instruction - protected InstructionHandle target; // Target object in instruction list - protected int position; // Byte code offset - - /** - * Empty constructor needed for the Class.newInstance() statement in - * Instruction.readInstruction(). Not to be used otherwise. - */ - BranchInstruction() {} - - /** Common super constructor - * @param opcodee Instruction opcode - * @param target instruction to branch to - */ - protected BranchInstruction(short opcode, InstructionHandle target) { - super(opcode, (short)3); - setTarget(target); - } - - /** - * Dump instruction as byte code to stream out. - * @param out Output stream - */ - @Override - public void dump(DataOutputStream out) throws IOException { - out.writeByte(opcode); - - index = getTargetOffset(); - - if(Math.abs(index) >= 32767) // too large for short - throw new ClassGenException("Branch target offset too large for short"); - - out.writeShort(index); // May be negative, i.e., point backwards - } - - /** - * @param target branch target - * @return the offset to `target' relative to this instruction - */ - protected int getTargetOffset(InstructionHandle target) { - if(target == null) - throw new ClassGenException("Target of " + super.toString(true) + - " is invalid null handle"); - - int t = target.getPosition(); - - if(t < 0) - throw new ClassGenException("Invalid branch target position offset for " + - super.toString(true) + ":" + t + ":" + target); - - return t - position; - } - - /** - * @return the offset to this instruction's target - */ - protected int getTargetOffset() { return getTargetOffset(target); } - - /** - * Called by InstructionList.setPositions when setting the position for every - * instruction. In the presence of variable length instructions `setPositions' - * performs multiple passes over the instruction list to calculate the - * correct (byte) positions and offsets by calling this function. - * - * @param offset additional offset caused by preceding (variable length) instructions - * @param max_offset the maximum offset that may be caused by these instructions - * @return additional offset caused by possible change of this instruction's length - */ - protected int updatePosition(int offset, int max_offset) { - position += offset; - return 0; - } - - /** - * Long output format: - * - * <position in byte code> - * <name of opcode> "["<opcode number>"]" - * "("<length of instruction>")" - * "<"<target instruction>">" "@"<branch target offset> - * - * @param verbose long/short format switch - * @return mnemonic for instruction - */ - @Override - public String toString(boolean verbose) { - String s = super.toString(verbose); - String t = "null"; - - if(verbose) { - if(target != null) { - if(target.getInstruction() == this) - t = "<points to itself>"; - else if(target.getInstruction() == null) - t = "<null instruction!!!?>"; - else - t = target.getInstruction().toString(false); // Avoid circles - } - } else { - if(target != null) { - index = getTargetOffset(); - t = "" + (index + position); - } - } - - return s + " -> " + t; - } - - /** - * Read needed data (e.g. index) from file. Conversion to a InstructionHandle - * is done in InstructionList(byte[]). - * - * @param bytes input stream - * @param wide wide prefix? - * @see InstructionList - */ - @Override - protected void initFromFile(ByteSequence bytes, boolean wide) throws IOException - { - length = 3; - index = bytes.readShort(); - } - - /** - * @return target offset in byte code - */ - public final int getIndex() { return index; } - - /** - * @return target of branch instruction - */ - public InstructionHandle getTarget() { return target; } - - /** - * Set branch target - * @param target branch target - */ - public final void setTarget(InstructionHandle target) { - notifyTargetChanging(this.target, this); - this.target = target; - notifyTargetChanged(this.target, this); - } - - /** - * Used by BranchInstruction, LocalVariableGen, CodeExceptionGen. - * Must be called before the target is actually changed in the - * InstructionTargeter. - */ - static void notifyTargetChanging(InstructionHandle old_ih, - InstructionTargeter t) { - if(old_ih != null) { - old_ih.removeTargeter(t); - } - } - - /** - * Used by BranchInstruction, LocalVariableGen, CodeExceptionGen. - * Must be called after the target is actually changed in the - * InstructionTargeter. - */ - static void notifyTargetChanged(InstructionHandle new_ih, - InstructionTargeter t) { - if(new_ih != null) { - new_ih.addTargeter(t); - } - } - - /** - * @param old_ih old target - * @param new_ih new target - */ - @Override - public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) { - if(target == old_ih) - setTarget(new_ih); - else - throw new ClassGenException("Not targeting " + old_ih + ", but " + target); - } - - /** - * @return true, if ih is target of this instruction - */ - @Override - public boolean containsTarget(InstructionHandle ih) { - return (target == ih); - } - - /** - * Inform target that it's not targeted anymore. - */ - @Override - void dispose() { - setTarget(null); - index=-1; - position=-1; - } -} |