RegisterFormatter.java revision 3c23129eecb7127646f2901c1b0ec3b94a83c08f 
1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2009 Ben Gruver
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.dexlib.CodeItem;
32import org.jf.baksmali.baksmali;
33
34/**
35 * This class contains the logic used for formatting registers
36 */
37public class RegisterFormatter {
38
39    /**
40     * This method is used (only) by format 3rc (the format that uses a range of regsiters like {v1 .. v10}) to format
41     * it's registers. If both registers are parameter registers, they will be formatted as such, otherwise they will
42     * both be formatted as normal registers
43     * @param codeItem
44     * @param startRegister
45     * @param lastRegister
46     * @return an array of 2 strings containing the formatted registers
47     */
48    public static String[] formatFormat3rcRegisters(CodeItem codeItem, int startRegister, int lastRegister) {
49        if (!baksmali.noParameterRegisters) {
50            int parameterRegisterCount = codeItem.getParent().method.getPrototype().getParameterRegisterCount()
51                + (codeItem.getParent().isDirect()?0:1);
52            int registerCount = codeItem.getRegisterCount();
53
54            assert startRegister <= lastRegister;
55
56            if (startRegister >= registerCount - parameterRegisterCount) {
57                return new String[] {"p" + (startRegister - (registerCount - parameterRegisterCount)),
58                                     "p" + (lastRegister - (registerCount - parameterRegisterCount))};
59            }
60        }
61        return new String[] {"v" + startRegister,
62                             "v" + lastRegister};
63    }
64
65    /**
66     * Formats a register with the appropriate format - with either the normal v<n> format or the p<n> parameter format.
67     *
68     * It uses the register and parameter information from the give <code>CodeItem</code> to determine if the given
69     * register is a normal or parameter register.
70     * @param codeItem
71     * @param register
72     * @return The formatted register
73     */
74    public static String formatRegister(CodeItem codeItem, int register) {
75        if (!baksmali.noParameterRegisters) {
76            int parameterRegisterCount = codeItem.getParent().method.getPrototype().getParameterRegisterCount()
77                + (codeItem.getParent().isDirect()?0:1);
78            int registerCount = codeItem.getRegisterCount();
79            if (register >= registerCount - parameterRegisterCount) {
80                return "p" + (register - (registerCount - parameterRegisterCount));
81            }
82        }
83        return "v" + register;
84    }
85}
86