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      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 
     32 package org.jf.dexlib2.util;
     33 
     34 import com.google.common.base.Predicate;
     35 import org.jf.dexlib2.AccessFlags;
     36 import org.jf.dexlib2.iface.Method;
     37 import org.jf.dexlib2.iface.reference.MethodReference;
     38 
     39 import javax.annotation.Nonnull;
     40 import javax.annotation.Nullable;
     41 import java.util.Collection;
     42 
     43 public final class MethodUtil {
     44     private static int directMask = AccessFlags.STATIC.getValue() | AccessFlags.PRIVATE.getValue() |
     45             AccessFlags.CONSTRUCTOR.getValue();
     46 
     47     public static Predicate<Method> METHOD_IS_DIRECT = new Predicate<Method>() {
     48         @Override public boolean apply(@Nullable Method input) {
     49             return input != null && isDirect(input);
     50         }
     51     };
     52 
     53     public static Predicate<Method> METHOD_IS_VIRTUAL = new Predicate<Method>() {
     54         @Override public boolean apply(@Nullable Method input) {
     55             return input != null && !isDirect(input);
     56         }
     57     };
     58 
     59     public static boolean isDirect(@Nonnull Method method) {
     60         return (method.getAccessFlags() & directMask) != 0;
     61     }
     62 
     63     public static boolean isStatic(@Nonnull Method method) {
     64         return AccessFlags.STATIC.isSet(method.getAccessFlags());
     65     }
     66 
     67     public static boolean isConstructor(@Nonnull MethodReference methodReference) {
     68         return methodReference.getName().equals("<init>");
     69     }
     70 
     71     public static int getParameterRegisterCount(@Nonnull Method method) {
     72         return getParameterRegisterCount(method, MethodUtil.isStatic(method));
     73     }
     74 
     75     public static int getParameterRegisterCount(@Nonnull MethodReference methodRef, boolean isStatic) {
     76         return getParameterRegisterCount(methodRef.getParameterTypes(), isStatic);
     77     }
     78 
     79     public static int getParameterRegisterCount(@Nonnull Collection<? extends CharSequence> parameterTypes,
     80                                                 boolean isStatic) {
     81         int regCount = 0;
     82         for (CharSequence paramType: parameterTypes) {
     83             int firstChar = paramType.charAt(0);
     84             if (firstChar == 'J' || firstChar == 'D') {
     85                 regCount += 2;
     86             } else {
     87                 regCount++;
     88             }
     89         }
     90         if (!isStatic) {
     91             regCount++;
     92         }
     93         return regCount;
     94     }
     95 
     96     private static char getShortyType(CharSequence type) {
     97         if (type.length() > 1) {
     98             return 'L';
     99         }
    100         return type.charAt(0);
    101     }
    102 
    103     public static String getShorty(Collection<? extends CharSequence> params, String returnType) {
    104         StringBuilder sb = new StringBuilder(params.size() + 1);
    105         sb.append(getShortyType(returnType));
    106         for (CharSequence typeRef: params) {
    107             sb.append(getShortyType(typeRef));
    108         }
    109         return sb.toString();
    110     }
    111 
    112     private MethodUtil() {}
    113 }
    114