1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.dex.code;
18
19import com.android.dx.rop.code.RegisterSpec;
20import com.android.dx.rop.code.RegisterSpecList;
21import com.android.dx.rop.code.RegisterSpecSet;
22import com.android.dx.rop.code.SourcePosition;
23import com.android.dx.ssa.RegisterMapper;
24
25/**
26 * Pseudo-instruction which is used to hold a snapshot of the
27 * state of local variable name mappings that exists immediately after
28 * the instance in an instruction array.
29 */
30public final class LocalSnapshot extends ZeroSizeInsn {
31    /** {@code non-null;} local state associated with this instance */
32    private final RegisterSpecSet locals;
33
34    /**
35     * Constructs an instance. The output address of this instance is initially
36     * unknown ({@code -1}).
37     *
38     * @param position {@code non-null;} source position
39     * @param locals {@code non-null;} associated local variable state
40     */
41    public LocalSnapshot(SourcePosition position, RegisterSpecSet locals) {
42        super(position);
43
44        if (locals == null) {
45            throw new NullPointerException("locals == null");
46        }
47
48        this.locals = locals;
49    }
50
51    /** {@inheritDoc} */
52    @Override
53    public DalvInsn withRegisterOffset(int delta) {
54        return new LocalSnapshot(getPosition(), locals.withOffset(delta));
55    }
56
57    /** {@inheritDoc} */
58    @Override
59    public DalvInsn withRegisters(RegisterSpecList registers) {
60        return new LocalSnapshot(getPosition(), locals);
61    }
62
63    /**
64     * Gets the local state associated with this instance.
65     *
66     * @return {@code non-null;} the state
67     */
68    public RegisterSpecSet getLocals() {
69        return locals;
70    }
71
72    /** {@inheritDoc} */
73    @Override
74    protected String argString() {
75        return locals.toString();
76    }
77
78    /** {@inheritDoc} */
79    @Override
80    protected String listingString0(boolean noteIndices) {
81        int sz = locals.size();
82        int max = locals.getMaxSize();
83        StringBuilder sb = new StringBuilder(100 + sz * 40);
84
85        sb.append("local-snapshot");
86
87        for (int i = 0; i < max; i++) {
88            RegisterSpec spec = locals.get(i);
89            if (spec != null) {
90                sb.append("\n  ");
91                sb.append(LocalStart.localString(spec));
92            }
93        }
94
95        return sb.toString();
96    }
97
98    /** {@inheritDoc} */
99    @Override
100    public DalvInsn withMapper(RegisterMapper mapper) {
101      return new LocalSnapshot(getPosition(), mapper.map(locals));
102    }
103}
104