/*

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

 * Copyright (c) 2019 SAP SE. 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

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 */

/**

 * @test

 * @summary Test NullPointerException messages thrown in frames that

 *   are hidden in the backtrace/stackTrace.

 * @bug 8218628

 * @library /test/lib

 * @compile -g NPEInHiddenTopFrameTest.java

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

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

 */

import jdk.test.lib.Asserts;

public class NPEInHiddenTopFrameTest {

    @FunctionalInterface

    private static interface SomeFunctionalInterface {

        String someMethod(String a, String b);

    }

    public static void checkMessage(String expression,

                                    String obtainedMsg, String expectedMsg) {

        System.out.println();

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

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

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

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

        Asserts.assertEquals(expectedMsg, obtainedMsg);

    }

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

        boolean framesAreHidden = false;

        if (args.length > 0) {

            String arg = args[0];

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

        }

        try {

            final SomeFunctionalInterface concatter = String::concat;

            final String nullString = null;

            if (concatter != null) {

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

                concatter.someMethod(nullString, "validString");

            }

        } catch (NullPointerException e) {

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

                         framesAreHidden ?

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

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

                         // " because 'concatter' is null."

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

                         // message. So we expect null:

                         null :

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

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

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

            e.printStackTrace();

        }

    }

}