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 24 /** 25 * @test 26 * @bug 8021897 27 * @summary Test getting the value for an uninitialized String object 28 * 29 * @author Staffan Larsen 30 * 31 * @modules jdk.jdi 32 * @run build TestScaffold VMConnection TargetListener TargetAdapter 33 * @run compile -g GetUninitializedStringValue.java 34 * @run driver GetUninitializedStringValue 35 */ 36 import com.sun.jdi.ReferenceType; 37 import com.sun.jdi.StackFrame; 38 import com.sun.jdi.StringReference; 39 import com.sun.jdi.ThreadReference; 40 import com.sun.jdi.event.BreakpointEvent; 41 42 /********** target program **********/ 43 44 class GetUninitializedStringValueTarg { 45 public static void main(String[] args) { 46 new String("foo"); 47 System.out.println("Goodbye from GetUninitializedStringValueTarg!"); 48 } 49 } 50 51 /********** test program **********/ 52 53 public class GetUninitializedStringValue extends TestScaffold { 54 ReferenceType targetClass; 55 ThreadReference mainThread; 56 57 GetUninitializedStringValue (String args[]) { 58 super(args); 59 } 60 61 public static void main(String[] args) 62 throws Exception 63 { 64 new GetUninitializedStringValue (args).startTests(); 65 } 66 67 /********** test core **********/ 68 69 protected void runTests() 70 throws Exception 71 { 72 /* 73 * Run to String.<init> 74 */ 75 startUp("GetUninitializedStringValueTarg"); 76 BreakpointEvent bpe = resumeTo("java.lang.String", "<init>", "(Ljava/lang/String;)V"); 77 78 /* 79 * We've arrived. Look at 'this' - it will be uninitialized (the value field will not be set yet). 80 */ 81 StackFrame frame = bpe.thread().frame(0); 82 StringReference sr = (StringReference)frame.thisObject(); 83 if (!sr.value().equals("")) { 84 throw new Exception("Unexpected value for the uninitialized String"); 85 } 86 87 /* 88 * resume the target listening for events 89 */ 90 listenUntilVMDisconnect(); 91 } 92 }