RegisterFormatter.java revision ffe82bdcb5c914b3a60b630c6d3abe6fc9229dec 
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.baksmali.baksmali;
32import org.jf.util.IndentingWriter;
33
34import java.io.IOException;
35
36/**
37 * This class contains the logic used for formatting registers
38 */
39public class RegisterFormatter {
40    public final int registerCount;
41    public final int parameterRegisterCount;
42
43    public RegisterFormatter(int registerCount, int parameterRegisterCount) {
44        this.registerCount = registerCount;
45        this.parameterRegisterCount = parameterRegisterCount;
46    }
47
48    /**
49     * Write out the register range value used by Format3rc. If baksmali.noParameterRegisters is true, it will always
50     * output the registers in the v<n> format. But if false, then it will check if *both* registers are parameter
51     * registers, and if so, use the p<n> format for both. If only the last register is a parameter register, it will
52     * use the v<n> format for both, otherwise it would be confusing to have something like {v20 .. p1}
53     * @param writer the <code>IndentingWriter</code> to write to
54     * @param startRegister the first register in the range
55     * @param lastRegister the last register in the range
56     */
57    public void writeRegisterRange(IndentingWriter writer, int startRegister, int lastRegister) throws IOException {
58        if (!baksmali.noParameterRegisters) {
59            assert startRegister <= lastRegister;
60
61            if (startRegister >= registerCount - parameterRegisterCount) {
62                writer.write("{p");
63                writer.printSignedIntAsDec(startRegister - (registerCount - parameterRegisterCount));
64                writer.write(" .. p");
65                writer.printSignedIntAsDec(lastRegister - (registerCount - parameterRegisterCount));
66                writer.write('}');
67                return;
68            }
69        }
70        writer.write("{v");
71        writer.printSignedIntAsDec(startRegister);
72        writer.write(" .. v");
73        writer.printSignedIntAsDec(lastRegister);
74        writer.write('}');
75    }
76
77    /**
78     * Writes a register with the appropriate format. If baksmali.noParameterRegisters is true, then it will always
79     * output a register in the v<n> format. If false, then it determines if the register is a parameter register,
80     * and if so, formats it in the p<n> format instead.
81     *
82     * @param writer the <code>IndentingWriter</code> to write to
83     * @param register the register number
84     */
85    public void writeTo(IndentingWriter writer, int register) throws IOException {
86        if (!baksmali.noParameterRegisters) {
87            if (register >= registerCount - parameterRegisterCount) {
88                writer.write('p');
89                writer.printSignedIntAsDec((register - (registerCount - parameterRegisterCount)));
90                return;
91            }
92        }
93        writer.write('v');
94        writer.printSignedIntAsDec(register);
95    }
96}
97