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.Opcode;
33import org.jf.dexlib.DexFile;
34import org.jf.dexlib.Util.AnnotatedOutput;
35import org.jf.dexlib.Util.NumberUtils;
36
37import java.util.Iterator;
38
39public class ArrayDataPseudoInstruction extends Instruction {
40    public static final Instruction.InstructionFactory Factory = new Factory();
41    private int elementWidth;
42    private byte[] encodedValues;
43
44    @Override
45    public int getSize(int codeAddress) {
46        return ((encodedValues.length + 1)/2) + 4 + (codeAddress % 2);
47    }
48
49    public ArrayDataPseudoInstruction(int elementWidth, byte[] encodedValues) {
50        super(Opcode.NOP);
51
52        if (encodedValues.length % elementWidth != 0) {
53            throw new RuntimeException("There are not a whole number of " + elementWidth + " byte elements");
54        }
55
56        this.elementWidth = elementWidth;
57        this.encodedValues = encodedValues;
58    }
59
60    public ArrayDataPseudoInstruction(byte[] buffer, int bufferIndex) {
61        super(Opcode.NOP);
62
63        byte opcodeByte = buffer[bufferIndex];
64        if (opcodeByte != 0x00) {
65            throw new RuntimeException("Invalid opcode byte for an ArrayData pseudo-instruction");
66        }
67
68        byte subopcodeByte = buffer[bufferIndex+1];
69        if (subopcodeByte != 0x03) {
70            throw new RuntimeException("Invalid sub-opcode byte for an ArrayData pseudo-instruction");
71        }
72
73        this.elementWidth = NumberUtils.decodeUnsignedShort(buffer, bufferIndex+2);
74        int elementCount = NumberUtils.decodeInt(buffer, bufferIndex+4);
75        this.encodedValues = new byte[elementCount * elementWidth];
76        System.arraycopy(buffer, bufferIndex+8, encodedValues, 0, elementCount * elementWidth);
77    }
78
79    protected void writeInstruction(AnnotatedOutput out, int currentCodeAddress) {
80        out.alignTo(4);
81
82        int elementCount = encodedValues.length / elementWidth;
83
84        out.writeByte(0x00);
85        out.writeByte(0x03);
86        out.writeShort(elementWidth);
87        out.writeInt(elementCount);
88        out.write(encodedValues);
89
90        //make sure we're written out an even number of bytes
91        out.alignTo(2);
92    }
93
94    protected void annotateInstruction(AnnotatedOutput out, int currentCodeAddress) {
95        out.annotate(getSize(currentCodeAddress)*2, "[0x" + Integer.toHexString(currentCodeAddress) + "] " +
96                "fill-array-data instruction");
97    }
98
99    public Format getFormat() {
100        return Format.ArrayData;
101    }
102
103    public int getElementWidth() {
104        return elementWidth;
105    }
106
107    public int getElementCount() {
108        return encodedValues.length / elementWidth;
109    }
110
111    public static class ArrayElement {
112        public final byte[] buffer;
113        public int bufferIndex;
114        public final int elementWidth;
115        public ArrayElement(byte[] buffer, int elementWidth) {
116            this.buffer = buffer;
117            this.elementWidth = elementWidth;
118        }
119    }
120
121    public Iterator<ArrayElement> getElements() {
122        return new Iterator<ArrayElement>() {
123            final int elementCount = getElementCount();
124            int i=0;
125            int position=0;
126            final ArrayElement arrayElement = new ArrayElement(encodedValues, getElementWidth());
127
128            public boolean hasNext() {
129                return i<elementCount;
130            }
131
132            public ArrayElement next() {
133                arrayElement.bufferIndex = position;
134                position += arrayElement.elementWidth;
135                i++;
136                return arrayElement;
137            }
138
139            public void remove() {
140            }
141        };
142    }
143
144    private static class Factory implements Instruction.InstructionFactory {
145        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
146            if (opcode != Opcode.NOP) {
147                throw new RuntimeException("The opcode for an ArrayDataPseudoInstruction must be NOP");
148            }
149            return new ArrayDataPseudoInstruction(buffer, bufferIndex);
150        }
151    }
152}
153