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.dexgen.rop.cst;
18
19import com.android.dexgen.rop.type.Prototype;
20import com.android.dexgen.rop.type.Type;
21import com.android.dexgen.rop.type.TypeBearer;
22
23/**
24 * Base class for constants of "methodish" type.
25 *
26 * <p><b>Note:</b> As a {@link TypeBearer}, this class bears the return type
27 * of the method.</p>
28 */
29public abstract class CstBaseMethodRef
30        extends CstMemberRef {
31    /** {@code non-null;} the raw prototype for this method */
32    private final Prototype prototype;
33
34    /**
35     * {@code null-ok;} the prototype for this method taken to be an instance
36     * method, or {@code null} if not yet calculated
37     */
38    private Prototype instancePrototype;
39
40    /**
41     * Constructs an instance.
42     *
43     * @param definingClass {@code non-null;} the type of the defining class
44     * @param nat {@code non-null;} the name-and-type
45     */
46    /*package*/ CstBaseMethodRef(CstType definingClass, CstNat nat) {
47        super(definingClass, nat);
48
49        String descriptor = getNat().getDescriptor().getString();
50        this.prototype = Prototype.intern(descriptor);
51        this.instancePrototype = null;
52    }
53
54    /**
55     * Gets the raw prototype of this method. This doesn't include a
56     * {@code this} argument.
57     *
58     * @return {@code non-null;} the method prototype
59     */
60    public final Prototype getPrototype() {
61        return prototype;
62    }
63
64    /**
65     * Gets the prototype of this method as either a
66     * {@code static} or instance method. In the case of a
67     * {@code static} method, this is the same as the raw
68     * prototype. In the case of an instance method, this has an
69     * appropriately-typed {@code this} argument as the first
70     * one.
71     *
72     * @param isStatic whether the method should be considered static
73     * @return {@code non-null;} the method prototype
74     */
75    public final Prototype getPrototype(boolean isStatic) {
76        if (isStatic) {
77            return prototype;
78        } else {
79            if (instancePrototype == null) {
80                Type thisType = getDefiningClass().getClassType();
81                instancePrototype = prototype.withFirstParameter(thisType);
82            }
83            return instancePrototype;
84        }
85    }
86
87    /** {@inheritDoc} */
88    @Override
89    protected final int compareTo0(Constant other) {
90        int cmp = super.compareTo0(other);
91
92        if (cmp != 0) {
93            return cmp;
94        }
95
96        CstBaseMethodRef otherMethod = (CstBaseMethodRef) other;
97        return prototype.compareTo(otherMethod.prototype);
98    }
99
100    /**
101     * {@inheritDoc}
102     *
103     * In this case, this method returns the <i>return type</i> of this method.
104     *
105     * @return {@code non-null;} the method's return type
106     */
107    public final Type getType() {
108        return prototype.getReturnType();
109    }
110
111    /**
112     * Gets the number of words of parameters required by this
113     * method's descriptor. Since instances of this class have no way
114     * to know if they will be used in a {@code static} or
115     * instance context, one has to indicate this explicitly as an
116     * argument. This method is just a convenient shorthand for
117     * {@code getPrototype().getParameterTypes().getWordCount()},
118     * plus {@code 1} if the method is to be treated as an
119     * instance method.
120     *
121     * @param isStatic whether the method should be considered static
122     * @return {@code >= 0;} the argument word count
123     */
124    public final int getParameterWordCount(boolean isStatic) {
125        return getPrototype(isStatic).getParameterTypes().getWordCount();
126    }
127
128    /**
129     * Gets whether this is a reference to an instance initialization
130     * method. This is just a convenient shorthand for
131     * {@code getNat().isInstanceInit()}.
132     *
133     * @return {@code true} iff this is a reference to an
134     * instance initialization method
135     */
136    public final boolean isInstanceInit() {
137        return getNat().isInstanceInit();
138    }
139
140    /**
141     * Gets whether this is a reference to a class initialization
142     * method. This is just a convenient shorthand for
143     * {@code getNat().isClassInit()}.
144     *
145     * @return {@code true} iff this is a reference to an
146     * instance initialization method
147     */
148    public final boolean isClassInit() {
149        return getNat().isClassInit();
150    }
151}
152