RegisterFormatter.java revision 4b72225e9d81201838f387171a68a832486903f9 
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;
30
31import org.jf.util.IndentingWriter;
32import org.jf.baksmali.baksmali;
33import org.jf.dexlib.CodeItem;
34import org.jf.dexlib.Util.AccessFlags;
35
36import java.io.IOException;
37
38/**
39 * This class contains the logic used for formatting registers
40 */
41public class RegisterFormatter {
42
43    /**
44     * Write out the register range value used by Format3rc. If baksmali.noParameterRegisters is true, it will always
45     * output the registers in the v<n> format. But if false, then it will check if *both* registers are parameter
46     * registers, and if so, use the p<n> format for both. If only the last register is a parameter register, it will
47     * use the v<n> format for both, otherwise it would be confusing to have something like {v20 .. p1}
48     * @param writer the <code>IndentingWriter</code> to write to
49     * @param codeItem the <code>CodeItem</code> that the register is from
50     * @param startRegister the first register in the range
51     * @param lastRegister the last register in the range
52     */
53    public static void writeRegisterRange(IndentingWriter writer, CodeItem codeItem, int startRegister,
54                                          int lastRegister) throws IOException {
55        assert lastRegister >= startRegister;
56
57        if (!baksmali.noParameterRegisters) {
58            int parameterRegisterCount = codeItem.getParent().method.getPrototype().getParameterRegisterCount()
59                + (((codeItem.getParent().accessFlags & AccessFlags.STATIC.getValue())==0)?1:0);
60            int registerCount = codeItem.getRegisterCount();
61
62            assert startRegister <= lastRegister;
63
64            if (startRegister >= registerCount - parameterRegisterCount) {
65                writer.write("{p");
66                writer.printIntAsDec(startRegister - (registerCount - parameterRegisterCount));
67                writer.write(" .. p");
68                writer.printIntAsDec(lastRegister - (registerCount - parameterRegisterCount));
69                writer.write('}');
70                return;
71            }
72        }
73        writer.write("{v");
74        writer.printIntAsDec(startRegister);
75        writer.write(" .. v");
76        writer.printIntAsDec(lastRegister);
77        writer.write('}');
78    }
79
80    /**
81     * Writes a register with the appropriate format. If baksmali.noParameterRegisters is true, then it will always
82     * output a register in the v<n> format. If false, then it determines if the register is a parameter register,
83     * and if so, formats it in the p<n> format instead.
84     *
85     * @param writer the <code>IndentingWriter</code> to write to
86     * @param codeItem the <code>CodeItem</code> that the register is from
87     * @param register the register number
88     */
89    public static void writeTo(IndentingWriter writer, CodeItem codeItem, int register) throws IOException {
90        if (!baksmali.noParameterRegisters) {
91            int parameterRegisterCount = codeItem.getParent().method.getPrototype().getParameterRegisterCount()
92                    + (((codeItem.getParent().accessFlags & AccessFlags.STATIC.getValue())==0)?1:0);
93            int registerCount = codeItem.getRegisterCount();
94            if (register >= registerCount - parameterRegisterCount) {
95                writer.write('p');
96                writer.printIntAsDec((register - (registerCount - parameterRegisterCount)));
97                return;
98            }
99        }
100        writer.write('v');
101        writer.printIntAsDec(register);
102    }
103}
104