| /* |
| * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 8027445 |
| * @summary String.equals() may be called with a length whose upper bits are not cleared |
| * |
| * @run main/othervm -XX:-UseOnStackReplacement -XX:-BackgroundCompilation |
| * compiler.intrinsics.string.TestStringEqualsBadLength |
| */ |
| |
| package compiler.intrinsics.string; |
| |
| import java.util.Arrays; |
| |
| public class TestStringEqualsBadLength { |
| |
| int v1; |
| int v2; |
| |
| boolean m(String s1) { |
| int l = v2 - v1; // 0 - (-1) = 1. On 64 bit: 0xffffffff00000001 |
| char[] arr = new char[l]; |
| arr[0] = 'a'; |
| String s2 = new String(arr); |
| // The string length is not reloaded but the value computed is |
| // reused so pointer computation must not use |
| // 0xffffffff00000001 |
| return s2.equals(s1); |
| } |
| |
| // Same thing with String.compareTo() |
| int m2(String s1) { |
| int l = v2 - v1; |
| char[] arr = new char[l+1]; |
| arr[0] = 'a'; |
| arr[1] = 'b'; |
| String s2 = new String(arr); |
| return s2.compareTo(s1); |
| } |
| |
| // Same thing with equals() for arrays |
| boolean m3(char[] arr1) { |
| int l = v2 - v1; // 0 - (-1) = 1. On 64 bit: 0xffffffff00000001 |
| char[] arr2 = new char[l]; |
| arr2[0] = 'a'; |
| return Arrays.equals(arr2, arr1); |
| } |
| |
| static public void main(String[] args) { |
| TestStringEqualsBadLength tse = new TestStringEqualsBadLength(); |
| tse.v1 = -1; |
| tse.v2 = 0; |
| char[] arr = new char[1]; |
| arr[0] = 'a'; |
| for (int i = 0; i < 20000; i++) { |
| tse.m("a"); |
| tse.m2("ab"); |
| tse.m3(arr); |
| } |
| |
| System.out.println("TEST PASSED"); |
| } |
| } |