1 /*
   2  * Copyright (c) 2016, 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
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  22  *
  23  */
  24 
  25 /**
  26  * @test
  27  * @bug 8148752
  28  * @summary Test correct casting of MH arguments during inlining.
  29  *
  30  * @run main compiler.jsr292.LongReferenceCastingTest
  31  */
  32 
  33 package compiler.jsr292;
  34 
  35 import java.lang.invoke.MethodHandle;
  36 import java.lang.invoke.MethodHandles;
  37 import java.lang.invoke.MethodType;
  38 
  39 public class LongReferenceCastingTest {
  40     static final String MY_STRING = "myString";
  41     static final MethodHandle MH;
  42 
  43     static {
  44         try {
  45             MethodHandles.Lookup lookup = MethodHandles.lookup();
  46             MethodType mt = MethodType.methodType(String.class, long.class, Object.class, String.class);
  47             MH = lookup.findVirtual(LongReferenceCastingTest.class, "myMethod", mt);
  48         } catch (Exception e) {
  49             throw new Error(e);
  50         }
  51     }
  52 
  53     public String myMethod(long l, Object o, String s) {
  54         // The long argument occupies two stack slots, causing C2 to treat it as
  55         // two arguments and casting the fist one two long and the second one to Object.
  56         // As a result, Object o is casted to String and the o.toString() call is
  57         // inlined as String::toString(). We fail at runtime because 'o' is not a String.
  58         return o.toString();
  59     }
  60 
  61     public String toString() {
  62         return MY_STRING;
  63     }
  64 
  65     public static void main(String[] args) throws Exception {
  66         LongReferenceCastingTest test = new LongReferenceCastingTest();
  67         try {
  68             for (int i = 0; i < 20_000; ++i) {
  69                 if (!test.invoke().equals(MY_STRING)) {
  70                     throw new RuntimeException("Invalid string");
  71                 }
  72             }
  73         } catch (Throwable t) {
  74             throw new RuntimeException("Test failed", t);
  75         }
  76     }
  77 
  78     public String invoke() throws Throwable {
  79         return (String) MH.invokeExact(this, 0L, (Object)this, MY_STRING);
  80     }
  81 }