1 /*

     2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

     3  * Copyright (c) 2019 SAP SE. All rights reserved.

     4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     5  *

     6  * This code is free software; you can redistribute it and/or modify it

     7  * under the terms of the GNU General Public License version 2 only, as

     8  * published by the Free Software Foundation.

     9  *

    10  * This code is distributed in the hope that it will be useful, but WITHOUT

    11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    13  * version 2 for more details (a copy is included in the LICENSE file that

    14  * accompanied this code).

    15  *

    16  * You should have received a copy of the GNU General Public License version

    17  * 2 along with this work; if not, write to the Free Software Foundation,

    18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    19  *

    20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    21  * or visit www.oracle.com if you need additional information or have any

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    24 

    25 /**

    26  * @test

    27  * @summary Test NullPointerException messages thrown in frames that

    28  *   are hidden in the backtrace/stackTrace.

    29  * @bug 8218628

    30  * @library /test/lib

    31  * @compile -g NPEInHiddenTopFrameTest.java

    32  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-ShowHiddenFrames -XX:+ShowCodeDetailsInExceptionMessages NPEInHiddenTopFrameTest hidden

    33  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+ShowHiddenFrames -XX:+ShowCodeDetailsInExceptionMessages NPEInHiddenTopFrameTest visible

    34  */

    35 

    36 import jdk.test.lib.Asserts;

    37 

    38 public class NPEInHiddenTopFrameTest {

    39 

    40     @FunctionalInterface

    41     private static interface SomeFunctionalInterface {

    42         String someMethod(String a, String b);

    43     }

    44 

    45     public static void checkMessage(String expression,

    46                                     String obtainedMsg, String expectedMsg) {

    47         System.out.println();

    48         System.out.println(" source code: " + expression);

    49         System.out.println("  thrown msg: " + obtainedMsg);

    50         if (obtainedMsg == null && expectedMsg == null) return;

    51         System.out.println("expected msg: " + expectedMsg);

    52         Asserts.assertEquals(expectedMsg, obtainedMsg);

    53     }

    54 

    55     public static void main(String[] args) throws Exception {

    56         boolean framesAreHidden = false;

    57         if (args.length > 0) {

    58             String arg = args[0];

    59             if (arg.equals("hidden")) framesAreHidden = true;

    60         }

    61 

    62         try {

    63             final SomeFunctionalInterface concatter = String::concat;

    64             final String nullString = null;

    65             if (concatter != null) {

    66                 // This throws NPE from the lambda expression which is a hidden frame.

    67                 concatter.someMethod(nullString, "validString");

    68             }

    69         } catch (NullPointerException e) {

    70             checkMessage("concatter.someMethod(nullString, \"validString\");", e.getMessage(),

    71                          framesAreHidden ?

    72                          // This is the message that would be printed if the wrong method/bci are used:

    73                          // "Cannot invoke 'NPEInHiddenTopFrameTest$SomeFunctionalInterface.someMethod(String, String)'" +

    74                          // " because 'concatter' is null."

    75                          // But the NPE message generation now recognizes this situation and skips the

    76                          // message. So we expect null:

    77                          null :

    78                          // This is the correct message, but it describes code generated on-the-fly.

    79                          // You get it if you disable hiding frames (-XX:+ShowHiddenframes).

    80                          "Cannot invoke \"String.concat(String)\" because \"<parameter1>\" is null" );

    81             e.printStackTrace();

    82         }

    83     }

    84 }