1/*
2 * Copyright 2012, Google Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 *     * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *     * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 *     * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32package org.jf.dexlib2.dexbacked;
33
34import org.jf.dexlib2.base.BaseTryBlock;
35import org.jf.dexlib2.dexbacked.raw.CodeItem;
36import org.jf.dexlib2.dexbacked.util.VariableSizeList;
37
38import javax.annotation.Nonnull;
39import java.util.List;
40
41public class DexBackedTryBlock extends BaseTryBlock<DexBackedExceptionHandler> {
42    @Nonnull public final DexBackedDexFile dexFile;
43    private final int tryItemOffset;
44    private final int handlersStartOffset;
45
46    public DexBackedTryBlock(@Nonnull DexBackedDexFile dexFile,
47                             int tryItemOffset,
48                             int handlersStartOffset) {
49        this.dexFile = dexFile;
50        this.tryItemOffset = tryItemOffset;
51        this.handlersStartOffset = handlersStartOffset;
52    }
53
54    @Override public int getStartCodeAddress() {
55        return dexFile.readSmallUint(tryItemOffset + CodeItem.TryItem.START_ADDRESS_OFFSET);
56    }
57
58    @Override public int getCodeUnitCount() {
59        return dexFile.readUshort(tryItemOffset + CodeItem.TryItem.CODE_UNIT_COUNT_OFFSET);
60    }
61
62    @Nonnull
63    @Override
64    public List<? extends DexBackedExceptionHandler> getExceptionHandlers() {
65        DexReader reader = dexFile.readerAt(
66                handlersStartOffset + dexFile.readUshort(tryItemOffset + CodeItem.TryItem.HANDLER_OFFSET));
67        final int encodedSize = reader.readSleb128();
68
69        if (encodedSize > 0) {
70            //no catch-all
71            return new VariableSizeList<DexBackedTypedExceptionHandler>(dexFile, reader.getOffset(), encodedSize) {
72                @Nonnull
73                @Override
74                protected DexBackedTypedExceptionHandler readNextItem(@Nonnull DexReader reader, int index) {
75                    return new DexBackedTypedExceptionHandler(reader);
76                }
77            };
78        } else {
79            //with catch-all
80            final int sizeWithCatchAll = (-1 * encodedSize) + 1;
81            return new VariableSizeList<DexBackedExceptionHandler>(dexFile, reader.getOffset(), sizeWithCatchAll) {
82                @Nonnull
83                @Override
84                protected DexBackedExceptionHandler readNextItem(@Nonnull DexReader dexReader, int index) {
85                    if (index == sizeWithCatchAll-1) {
86                        return new DexBackedCatchAllExceptionHandler(dexReader);
87                    } else {
88                        return new DexBackedTypedExceptionHandler(dexReader);
89                    }
90                }
91            };
92        }
93    }
94}
95