1 /*
   2  * Copyright (c) 2013, 2015, 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 package org.graalvm.compiler.replacements;
  24 
  25 import org.graalvm.compiler.api.replacements.ClassSubstitution;
  26 import org.graalvm.compiler.api.replacements.MethodSubstitution;
  27 import org.graalvm.compiler.core.common.SuppressFBWarnings;
  28 import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;
  29 import org.graalvm.compiler.nodes.java.LoadFieldNode;
  30 import org.graalvm.compiler.replacements.nodes.ArrayEqualsNode;
  31 
  32 // JaCoCo Exclude
  33 
  34 /**
  35  * Substitutions for {@link java.lang.String} methods.
  36  */
  37 @ClassSubstitution(String.class)
  38 public class StringSubstitutions {
  39 
  40     @MethodSubstitution(isStatic = false)
  41     @SuppressFBWarnings(value = "ES_COMPARING_PARAMETER_STRING_WITH_EQ", justification = "reference equality on the receiver is what we want")
  42     public static boolean equals(final String thisString, Object obj) {
  43         if (thisString == obj) {
  44             return true;
  45         }
  46         if (!(obj instanceof String)) {
  47             return false;
  48         }
  49         String thatString = (String) obj;
  50         if (thisString.length() != thatString.length()) {
  51             return false;
  52         }
  53         if (thisString.length() == 0) {
  54             return true;
  55         }
  56 
  57         final char[] array1 = getValue(thisString);
  58         final char[] array2 = getValue(thatString);
  59 
  60         return ArrayEqualsNode.equals(array1, array2, array1.length);
  61     }
  62 
  63     /**
  64      * Will be intrinsified with an {@link InvocationPlugin} to a {@link LoadFieldNode}.
  65      */
  66     private static native char[] getValue(String s);
  67 }