1 /* 2 * Copyright (c) 2018, Red Hat, Inc. 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 * @test 8214862 26 * @summary Multiple passes of PhaseRemoveUseless causes infinite loop to be optimized out 27 * 28 * @run main/othervm -XX:-TieredCompilation -Xcomp -XX:CompileOnly=StringConcatInfiniteLoop::test -XX:CompileCommand=dontinline,*StringBuilder::* StringConcatInfiniteLoop 29 * 30 */ 31 32 public class StringConcatInfiniteLoop { 33 public static void main(String[] args) { 34 StringBuilder sb = new StringBuilder(); 35 test(sb, "foo", "bar", true); 36 } 37 38 private static void test(Object v, String s1, String s2, boolean flag) { 39 if (flag) { 40 return; 41 } 42 int i = 0; 43 for (; i < 10; i++); 44 if (i == 10) { 45 v = null; 46 } 47 StringBuilder sb = new StringBuilder(s1); 48 sb.append(s2); 49 while (v == null); 50 } 51 52 private static class A { 53 } 54 }