1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 package org.graalvm.compiler.replacements;
  26 
  27 import org.graalvm.compiler.api.replacements.ClassSubstitution;
  28 import org.graalvm.compiler.api.replacements.MethodSubstitution;
  29 import org.graalvm.compiler.core.common.SuppressFBWarnings;
  30 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;
  31 import org.graalvm.compiler.nodes.java.LoadFieldNode;
  32 import org.graalvm.compiler.replacements.nodes.ArrayEqualsNode;
  33 
  34 // JaCoCo Exclude
  35 
  36 /**
  37  * Substitutions for {@link String} methods for JDK9 and later.
  38  *
  39  * {@link String} changed in JDK9 to contain a byte array instead of a char array. We therefore need
  40  * new substitutions for the related methods.
  41  */
  42 @ClassSubstitution(String.class)
  43 public class JDK9StringSubstitutions {
  44 
  45     @MethodSubstitution(isStatic = false)
  46     @SuppressFBWarnings(value = "ES_COMPARING_PARAMETER_STRING_WITH_EQ", justification = "reference equality on the receiver is what we want")
  47     public static boolean equals(final String thisString, Object obj) {
  48         if (thisString == obj) {
  49             return true;
  50         }
  51         if (!(obj instanceof String)) {
  52             return false;
  53         }
  54         String thatString = (String) obj;
  55         if (thisString.length() != thatString.length()) {
  56             return false;
  57         }
  58 
  59         if (thisString.length() == 0) {
  60             return true;
  61         }
  62         if (getCoder(thisString) != getCoder(thatString)) {
  63             return false;
  64         }
  65 
  66         final byte[] array1 = getValue(thisString);
  67         final byte[] array2 = getValue(thatString);
  68 
  69         return ArrayEqualsNode.equals(array1, array2, array1.length);
  70     }
  71 
  72     /**
  73      * Will be intrinsified with an {@link InvocationPlugin} to a {@link LoadFieldNode}.
  74      */
  75     public static native byte[] getValue(String s);
  76 
  77     public static native int getCoder(String s);
  78 }