1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2010 Ben Gruver (JesusFreke)
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29package org.jf.dexlib.Code.Format;
30
31import org.jf.dexlib.Code.Instruction;
32import org.jf.dexlib.Code.OffsetInstruction;
33import org.jf.dexlib.Code.Opcode;
34import org.jf.dexlib.Code.TwoRegisterInstruction;
35import org.jf.dexlib.DexFile;
36import org.jf.dexlib.Util.AnnotatedOutput;
37import org.jf.dexlib.Util.NumberUtils;
38
39public class Instruction22t extends Instruction implements OffsetInstruction, TwoRegisterInstruction {
40    public static final Instruction.InstructionFactory Factory = new Factory();
41    private byte regA;
42    private byte regB;
43    private short targetAddressOffset;
44
45    public Instruction22t(Opcode opcode, byte regA, byte regB, short offC) {
46        super(opcode);
47
48        if (regA >= 16 ||
49                regB >= 16) {
50            throw new RuntimeException("The register number must be less than v16");
51        }
52
53        if (offC == 0) {
54            throw new RuntimeException("The address offset cannot be 0.");
55        }
56
57        this.regA = regA;
58        this.regB = regB;
59        this.targetAddressOffset = offC;
60    }
61
62    private Instruction22t(Opcode opcode, byte[] buffer, int bufferIndex) {
63        super(opcode);
64
65        assert buffer[bufferIndex] == opcode.value;
66
67        regA = NumberUtils.decodeLowUnsignedNibble(buffer[bufferIndex + 1]);
68        regB = NumberUtils.decodeHighUnsignedNibble(buffer[bufferIndex + 1]);
69        targetAddressOffset = NumberUtils.decodeShort(buffer, bufferIndex + 2);
70
71        assert targetAddressOffset != 0;
72    }
73
74    protected void writeInstruction(AnnotatedOutput out, int currentCodeAddress) {
75        out.writeByte(opcode.value);
76        out.writeByte((regB << 4) | regA);
77        out.writeShort(targetAddressOffset);
78    }
79
80    public void updateTargetAddressOffset(int targetAddressOffset) {
81        if (targetAddressOffset < -32768 || targetAddressOffset > 32767) {
82            throw new RuntimeException("The address offset " + targetAddressOffset +
83                    " is out of range. It must be in [-32768, 32767]");
84        }
85        if (targetAddressOffset == 0) {
86            throw new RuntimeException("The address offset cannot be 0");
87        }
88        this.targetAddressOffset = (short)targetAddressOffset;
89    }
90
91    public Format getFormat() {
92        return Format.Format22t;
93    }
94
95    public int getRegisterA() {
96        return regA;
97    }
98
99    public int getRegisterB() {
100        return regB;
101    }
102
103    public int getTargetAddressOffset() {
104        return targetAddressOffset;
105    }
106
107    private static class Factory implements Instruction.InstructionFactory {
108        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
109            return new Instruction22t(opcode, buffer, bufferIndex);
110        }
111    }
112}