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 
17 package com.android.dx.rop.cst;
18 
19 import com.android.dx.rop.type.Prototype;
20 import com.android.dx.rop.type.Type;
21 import com.android.dx.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  */
29 public 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      */
CstBaseMethodRef(CstType definingClass, CstNat nat)46     /*package*/ CstBaseMethodRef(CstType definingClass, CstNat nat) {
47         super(definingClass, nat);
48 
49         String descriptor = getNat().getDescriptor().getString();
50         if (isSignaturePolymorphic()) {
51             // The prototype for signature polymorphic methods is used to
52             // construct call-site information and select the true invocation
53             // target (invoke() or invokeExact(). The prototype is created
54             // without being interned to avoid polluting the DEX file with
55             // unused data.
56             this.prototype = Prototype.fromDescriptor(descriptor);
57         } else {
58             this.prototype = Prototype.intern(descriptor);
59         }
60         this.instancePrototype = null;
61     }
62 
63     /**
64      * Gets the raw prototype of this method. This doesn't include a
65      * {@code this} argument.
66      *
67      * @return {@code non-null;} the method prototype
68      */
getPrototype()69     public final Prototype getPrototype() {
70         return prototype;
71     }
72 
73     /**
74      * Gets the prototype of this method as either a
75      * {@code static} or instance method. In the case of a
76      * {@code static} method, this is the same as the raw
77      * prototype. In the case of an instance method, this has an
78      * appropriately-typed {@code this} argument as the first
79      * one.
80      *
81      * @param isStatic whether the method should be considered static
82      * @return {@code non-null;} the method prototype
83      */
getPrototype(boolean isStatic)84     public final Prototype getPrototype(boolean isStatic) {
85         if (isStatic) {
86             return prototype;
87         } else {
88             if (instancePrototype == null) {
89                 Type thisType = getDefiningClass().getClassType();
90                 instancePrototype = prototype.withFirstParameter(thisType);
91             }
92             return instancePrototype;
93         }
94     }
95 
96     /** {@inheritDoc} */
97     @Override
compareTo0(Constant other)98     protected final int compareTo0(Constant other) {
99         int cmp = super.compareTo0(other);
100 
101         if (cmp != 0) {
102             return cmp;
103         }
104 
105         CstBaseMethodRef otherMethod = (CstBaseMethodRef) other;
106         return prototype.compareTo(otherMethod.prototype);
107     }
108 
109     /**
110      * {@inheritDoc}
111      *
112      * In this case, this method returns the <i>return type</i> of this method.
113      *
114      * @return {@code non-null;} the method's return type
115      */
116     @Override
getType()117     public final Type getType() {
118         return prototype.getReturnType();
119     }
120 
121     /**
122      * Gets the number of words of parameters required by this
123      * method's descriptor. Since instances of this class have no way
124      * to know if they will be used in a {@code static} or
125      * instance context, one has to indicate this explicitly as an
126      * argument. This method is just a convenient shorthand for
127      * {@code getPrototype().getParameterTypes().getWordCount()},
128      * plus {@code 1} if the method is to be treated as an
129      * instance method.
130      *
131      * @param isStatic whether the method should be considered static
132      * @return {@code >= 0;} the argument word count
133      */
getParameterWordCount(boolean isStatic)134     public final int getParameterWordCount(boolean isStatic) {
135         return getPrototype(isStatic).getParameterTypes().getWordCount();
136     }
137 
138     /**
139      * Gets whether this is a reference to an instance initialization
140      * method. This is just a convenient shorthand for
141      * {@code getNat().isInstanceInit()}.
142      *
143      * @return {@code true} iff this is a reference to an
144      * instance initialization method
145      */
isInstanceInit()146     public final boolean isInstanceInit() {
147         return getNat().isInstanceInit();
148     }
149 
150     /**
151      * Gets whether this is a reference to a class initialization
152      * method. This is just a convenient shorthand for
153      * {@code getNat().isClassInit()}.
154      *
155      * @return {@code true} iff this is a reference to an
156      * instance initialization method
157      */
isClassInit()158     public final boolean isClassInit() {
159         return getNat().isClassInit();
160     }
161 
162     /**
163      * Get whether this is a reference to a signature polymorphic
164      * method. This means it is defined in {@code java.lang.invoke.MethodHandle} and
165      * is either the {@code invoke} or the {@code invokeExact} method.
166      *
167      * @return {@code true} iff this is a reference to a
168      * signature polymorphic method.
169      */
isSignaturePolymorphic()170     public final boolean isSignaturePolymorphic() {
171         CstType definingClass = getDefiningClass();
172         if (definingClass.equals(CstType.METHOD_HANDLE)) {
173             switch (getNat().getName().getString()) {
174                 case "invoke":
175                 case "invokeExact":
176                     return true;
177             }
178         } else if (definingClass.equals(CstType.VAR_HANDLE)) {
179             switch (getNat().getName().getString()) {
180                 case "compareAndExchange":
181                 case "compareAndExchangeAcquire":
182                 case "compareAndExchangeRelease":
183                 case "compareAndSet":
184                 case "get":
185                 case "getAcquire":
186                 case "getAndAdd":
187                 case "getAndAddAcquire":
188                 case "getAndAddRelease":
189                 case "getAndBitwiseAnd":
190                 case "getAndBitwiseAndAcquire":
191                 case "getAndBitwiseAndRelease":
192                 case "getAndBitwiseOr":
193                 case "getAndBitwiseOrAcquire":
194                 case "getAndBitwiseOrRelease":
195                 case "getAndBitwiseXor":
196                 case "getAndBitwiseXorAcquire":
197                 case "getAndBitwiseXorRelease":
198                 case "getAndSet":
199                 case "getAndSetAcquire":
200                 case "getAndSetRelease":
201                 case "getOpaque":
202                 case "getVolatile":
203                 case "set":
204                 case "setOpaque":
205                 case "setRelease":
206                 case "setVolatile":
207                 case "weakCompareAndSet":
208                 case "weakCompareAndSetAcquire":
209                 case "weakCompareAndSetPlain":
210                 case "weakCompareAndSetRelease":
211                     return true;
212             }
213         }
214         return false;
215     }
216 }
217