1/*
2 * Copyright 2013, 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.analysis;
33
34import com.google.common.base.Strings;
35import org.jf.dexlib2.iface.Method;
36import org.jf.dexlib2.iface.reference.FieldReference;
37import org.jf.dexlib2.iface.reference.MethodReference;
38import org.jf.dexlib2.immutable.reference.ImmutableFieldReference;
39import org.jf.dexlib2.util.TypeUtils;
40import org.jf.util.ExceptionWithContext;
41
42import javax.annotation.Nonnull;
43import javax.annotation.Nullable;
44
45public class ArrayProto implements TypeProto {
46    protected final ClassPath classPath;
47    protected final int dimensions;
48    protected final String elementType;
49
50    public ArrayProto(@Nonnull ClassPath classPath, @Nonnull String type) {
51        this.classPath = classPath;
52        int i=0;
53        while (type.charAt(i) == '[') {
54            i++;
55            if (i == type.length()) {
56                throw new ExceptionWithContext("Invalid array type: %s", type);
57            }
58        }
59
60        if (i == 0) {
61            throw new ExceptionWithContext("Invalid array type: %s", type);
62        }
63
64        dimensions = i;
65        elementType = type.substring(i);
66    }
67
68    @Override public String toString() { return getType(); }
69    @Nonnull @Override public ClassPath getClassPath() { return classPath; }
70    @Nonnull @Override public String getType() { return makeArrayType(elementType, dimensions); }
71    public int getDimensions() { return dimensions; }
72    @Override public boolean isInterface() { return false; }
73
74    /**
75     * @return The base element type of this array. E.g. This would return Ljava/lang/String; for [[Ljava/lang/String;
76     */
77    @Nonnull public String getElementType() { return elementType; }
78
79    /**
80     * @return The immediate element type of this array. E.g. This would return [Ljava/lang/String; for
81     * [[Ljava/lang/String;
82     */
83    @Nonnull public String getImmediateElementType() {
84        if (dimensions > 1) {
85            return makeArrayType(elementType, dimensions-1);
86        }
87        return elementType;
88    }
89
90    @Override public boolean implementsInterface(@Nonnull String iface) {
91        return iface.equals("Ljava/lang/Cloneable;") || iface.equals("Ljava/io/Serializable;");
92    }
93
94    @Nullable @Override
95    public String getSuperclass() {
96        return "Ljava/lang/Object;";
97    }
98
99    @Nonnull @Override
100    public TypeProto getCommonSuperclass(@Nonnull TypeProto other) {
101        if (other instanceof ArrayProto) {
102            if (TypeUtils.isPrimitiveType(getElementType()) ||
103                    TypeUtils.isPrimitiveType(((ArrayProto)other).getElementType())) {
104                if (dimensions == ((ArrayProto)other).dimensions &&
105                        getElementType().equals(((ArrayProto)other).getElementType())) {
106                    return this;
107                }
108                return classPath.getClass("Ljava/lang/Object;");
109            }
110
111            if (dimensions == ((ArrayProto)other).dimensions) {
112                TypeProto thisClass = classPath.getClass(elementType);
113                TypeProto otherClass = classPath.getClass(((ArrayProto)other).elementType);
114                TypeProto mergedClass = thisClass.getCommonSuperclass(otherClass);
115                if (thisClass == mergedClass) {
116                    return this;
117                }
118                if (otherClass == mergedClass) {
119                    return other;
120                }
121                return classPath.getClass(makeArrayType(mergedClass.getType(), dimensions));
122            }
123
124            int dimensions = Math.min(this.dimensions, ((ArrayProto)other).dimensions);
125            return classPath.getClass(makeArrayType("Ljava/lang/Object;", dimensions));
126        }
127
128        if (other instanceof ClassProto) {
129            try {
130                if (other.isInterface()) {
131                    if (implementsInterface(other.getType())) {
132                        return other;
133                    }
134                }
135            } catch (UnresolvedClassException ex) {
136                // ignore
137            }
138            return classPath.getClass("Ljava/lang/Object;");
139        }
140
141        // otherwise, defer to the other class' getCommonSuperclass
142        return other.getCommonSuperclass(this);
143    }
144
145    private static final String BRACKETS = Strings.repeat("[", 256);
146
147    @Nonnull
148    private static String makeArrayType(@Nonnull String elementType, int dimensions) {
149        return BRACKETS.substring(0, dimensions) + elementType;
150    }
151
152
153    @Override
154    @Nullable
155    public FieldReference getFieldByOffset(int fieldOffset) {
156        if (fieldOffset==8) {
157            return new ImmutableFieldReference(getType(), "length", "int");
158        }
159        return null;
160    }
161
162    @Override
163    @Nullable
164    public Method getMethodByVtableIndex(int vtableIndex) {
165        return classPath.getClass("Ljava/lang/Object;").getMethodByVtableIndex(vtableIndex);
166    }
167
168    @Override public int findMethodIndexInVtable(@Nonnull MethodReference method) {
169        return classPath.getClass("Ljava/lang/Object;").findMethodIndexInVtable(method);
170    }
171}
172