1 /*
   2  * Copyright (c) 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 8020968
  27  * @summary Basic test for hidden frames
  28  * @run main HiddenFrames
  29  */
  30 
  31 import java.lang.StackWalker.Option;
  32 import java.lang.StackWalker.StackFrame;
  33 import java.lang.reflect.Method;
  34 import java.util.ArrayList;
  35 import java.util.Arrays;
  36 import java.util.List;
  37 import java.util.stream.Stream;
  38 
  39 public class HiddenFrames {
  40     public static void main(String... args) throws Exception {
  41         new HiddenFrames().test();
  42         new HiddenFrames(Option.SHOW_REFLECT_FRAMES).test();
  43         new HiddenFrames(Option.SHOW_HIDDEN_FRAMES).test();
  44     }
  45 
  46     private final Option option;
  47     private final StackWalker walker;
  48     private final List<StackFrame> lambdas = new ArrayList<>();
  49     private final List<StackFrame> reflects = new ArrayList<>();
  50 
  51     HiddenFrames() {
  52         this.option = null;
  53         this.walker = StackWalker.create();
  54     }
  55     HiddenFrames(Option option) {
  56         this.option = option;
  57         this.walker = StackWalker.create(option);
  58     }
  59 
  60     void test() throws Exception {
  61         walk();
  62         walkFromReflection();
  63     }
  64 
  65     void walk() {
  66        Stream.of(0).forEach(i -> walker.walk(s ->
  67        {
  68            s.forEach(this::checkFrame);
  69            return null;
  70        }));
  71 
  72         // only check hidden frames but not reflection frames
  73         // walk is not invoked via reflection
  74         if (option == null && !lambdas.isEmpty()) {
  75             throw new RuntimeException("Hidden frames are shown");
  76         }
  77 
  78         if (option == Option.SHOW_HIDDEN_FRAMES && lambdas.isEmpty()) {
  79             throw new RuntimeException("No hidden Lambda frame");
  80         }
  81     }
  82 
  83     void walkFromReflection() throws Exception {
  84         Method m = HiddenFrames.class.getDeclaredMethod("walk");
  85         m.invoke(this);
  86 
  87         if (option == null && !lambdas.isEmpty()) {
  88             throw new RuntimeException("Hidden frames are shown");
  89         }
  90 
  91         if (option == Option.SHOW_HIDDEN_FRAMES && lambdas.isEmpty()) {
  92             throw new RuntimeException("No hidden Lambda frame");
  93         }
  94 
  95         if (option != null && reflects.isEmpty()) {
  96             throw new RuntimeException("No reflection frame");
  97         }
  98     }
  99 
 100     void checkFrame(StackFrame frame) {
 101         String cn = frame.getClassName();
 102         if (cn.startsWith("java.lang.reflect.") || cn.startsWith("sun.reflect.")) {
 103             reflects.add(frame);
 104         }
 105         if (cn.contains("$$Lambda$")) {
 106             lambdas.add(frame);
 107         }
 108     }
 109 }