SparseSwitchMethodItem.java revision 09058f9914385025020e01125452a884f1b1fe11 
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.baksmali.Adaptors.Format;
30
31import org.jf.baksmali.Adaptors.LabelMethodItem;
32import org.jf.baksmali.Adaptors.MethodDefinition;
33import org.jf.dexlib2.iface.instruction.SwitchElement;
34import org.jf.dexlib2.iface.instruction.formats.SparseSwitchPayload;
35import org.jf.util.IndentingWriter;
36import org.jf.baksmali.Renderers.IntegerRenderer;
37
38import java.io.IOException;
39import java.util.ArrayList;
40import java.util.List;
41
42public class SparseSwitchMethodItem extends InstructionMethodItem<SparseSwitchPayload> {
43    private final List<SparseSwitchTarget> targets;
44
45    public SparseSwitchMethodItem(MethodDefinition methodDef, int codeAddress, SparseSwitchPayload instruction) {
46        super(methodDef, codeAddress, instruction);
47
48        int baseCodeAddress = methodDef.getSparseSwitchBaseAddress(codeAddress);
49
50        targets = new ArrayList<SparseSwitchTarget>();
51        if (baseCodeAddress >= 0) {
52            for (SwitchElement switchElement: instruction.getSwitchElements()) {
53                LabelMethodItem label = methodDef.getLabelCache().internLabel(
54                        new LabelMethodItem(baseCodeAddress + switchElement.getOffset(), "sswitch_"));
55                targets.add(new SparseSwitchLabelTarget(switchElement.getKey(), label));
56            }
57        } else {
58            //if we couldn't determine a base address, just use relative offsets rather than labels
59            for (SwitchElement switchElement: instruction.getSwitchElements()) {
60                targets.add(new SparseSwitchOffsetTarget(switchElement.getKey(), switchElement.getOffset()));
61            }
62        }
63    }
64
65    @Override
66    public boolean writeTo(IndentingWriter writer) throws IOException {
67        writer.write(".sparse-switch\n");
68        writer.indent(4);
69        for (SparseSwitchTarget target: targets) {
70            IntegerRenderer.writeTo(writer, target.getKey());
71            writer.write(" -> ");
72            target.writeTargetTo(writer);
73            writer.write('\n');
74        }
75        writer.deindent(4);
76        writer.write(".end sparse-switch");
77        return true;
78    }
79
80    private static abstract class SparseSwitchTarget {
81        private final int key;
82        public SparseSwitchTarget(int key) {
83            this.key = key;
84        }
85        public int getKey() { return key; }
86        public abstract void writeTargetTo(IndentingWriter writer) throws IOException;
87    }
88
89    private static class SparseSwitchLabelTarget extends SparseSwitchTarget {
90        private final LabelMethodItem target;
91        public SparseSwitchLabelTarget(int key, LabelMethodItem target) {
92            super(key);
93            this.target = target;
94        }
95
96        public void writeTargetTo(IndentingWriter writer) throws IOException {
97            target.writeTo(writer);
98        }
99    }
100
101    private static class SparseSwitchOffsetTarget extends SparseSwitchTarget {
102        private final int target;
103        public SparseSwitchOffsetTarget(int key, int target) {
104            super(key);
105            this.target = target;
106        }
107
108        public void writeTargetTo(IndentingWriter writer) throws IOException {
109            if (target >= 0) {
110                writer.write('+');
111            }
112            writer.printSignedIntAsDec(target);
113        }
114    }
115}
116