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.InstructionWithReference;
33import org.jf.dexlib.Code.Opcode;
34import org.jf.dexlib.Code.SingleRegisterInstruction;
35import org.jf.dexlib.DexFile;
36import org.jf.dexlib.Item;
37import org.jf.dexlib.TypeIdItem;
38import org.jf.dexlib.Util.AnnotatedOutput;
39
40public class Instruction21c extends InstructionWithReference implements SingleRegisterInstruction {
41    public static final Instruction.InstructionFactory Factory = new Factory();
42    private byte regA;
43
44    public Instruction21c(Opcode opcode, short regA, Item referencedItem) {
45        super(opcode, referencedItem);
46
47        if (regA >= 1 << 8) {
48            throw new RuntimeException("The register number must be less than v256");
49        }
50
51        if (opcode == Opcode.NEW_INSTANCE) {
52            assert referencedItem instanceof TypeIdItem;
53            if (((TypeIdItem)referencedItem).getTypeDescriptor().charAt(0) != 'L') {
54                throw new RuntimeException("Only class references can be used with the new-instance opcode");
55            }
56        }
57
58        this.regA = (byte)regA;
59    }
60
61    private Instruction21c(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
62        super(dexFile, opcode, buffer, bufferIndex);
63
64        if (opcode == Opcode.NEW_INSTANCE &&
65                ((TypeIdItem)this.getReferencedItem()).getTypeDescriptor().charAt(0) != 'L') {
66
67            throw new RuntimeException("Only class references can be used with the new-instance opcode");
68        }
69
70        this.regA = buffer[bufferIndex + 1];
71    }
72
73    protected void writeInstruction(AnnotatedOutput out, int currentCodeAddress) {
74        if(opcode == Opcode.CONST_STRING && getReferencedItem().getIndex() > 0xFFFF) {
75            throw new RuntimeException("String offset is too large for const-string. Use string-const/jumbo instead.");
76        }
77
78        out.writeByte(opcode.value);
79        out.writeByte(regA);
80        out.writeShort(getReferencedItem().getIndex());
81    }
82
83    public Format getFormat() {
84        return Format.Format21c;
85    }
86
87    public int getRegisterA() {
88        return regA & 0xFF;
89    }
90
91    private static class Factory implements Instruction.InstructionFactory {
92        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
93            return new Instruction21c(dexFile, opcode, buffer, bufferIndex);
94        }
95    }
96}
97