1 /*
   2  * Copyright (c) 2015, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /* @test
  27  * @bug 8160717
  28  * @run main/othervm -ea -esa -Djava.lang.invoke.MethodHandle.COMPILE_THRESHOLD=-1 test.java.lang.invoke.LoopCombinatorLongSignatureTest
  29  * @run main/othervm -ea -esa test.java.lang.invoke.LoopCombinatorLongSignatureTest
  30  */
  31 
  32 package test.java.lang.invoke;
  33 
  34 import java.lang.invoke.MethodHandle;
  35 import java.lang.invoke.MethodHandles;
  36 import java.util.Arrays;
  37 
  38 /**
  39  * If a loop with an excessive amount of clauses is created, so that the number of parameters to the resulting loop
  40  * handle exceeds the allowed maximum, an IAE must be signalled. The test is run first in LambdaForm interpretation mode
  41  * and then in default mode, wherein bytecode generation falls back to LFI mode due to excessively long methods.
  42  */
  43 public class LoopCombinatorLongSignatureTest {
  44 
  45     static final MethodHandle INIT = MethodHandles.constant(int.class, 0);
  46     static final MethodHandle STEP = MethodHandles.identity(int.class);
  47     static final MethodHandle PRED_F = MethodHandles.constant(boolean.class, false);
  48     static final MethodHandle PRED_T = MethodHandles.constant(boolean.class, true);
  49     static final MethodHandle FINI = MethodHandles.identity(int.class);
  50 
  51     static final int ARG_LIMIT = 254; // for internal reasons, this is the maximum allowed number of arguments
  52 
  53     public static void main(String[] args) {
  54         for (int loopArgs = 0; loopArgs < 2; ++loopArgs) {
  55             testLongSignature(loopArgs, false);
  56             testLongSignature(loopArgs, true);
  57         }
  58     }
  59 
  60     static void testLongSignature(int loopArgs, boolean excessive) {
  61         int nClauses = ARG_LIMIT - loopArgs + (excessive ? 1 : 0);
  62 
  63         System.out.print((excessive ? "(EXCESSIVE)" : "(LONG     )") + " arguments: " + loopArgs + ", clauses: " + nClauses + " -> ");
  64 
  65         // extend init to denote what arguments the loop should accept
  66         Class<?>[] argTypes = new Class<?>[loopArgs];
  67         Arrays.fill(argTypes, int.class);
  68         MethodHandle init = MethodHandles.dropArguments(INIT, 0, argTypes);
  69 
  70         // build clauses
  71         MethodHandle[][] clauses = new MethodHandle[nClauses][];
  72         MethodHandle[] clause = {init, STEP, PRED_T, FINI};
  73         MethodHandle[] fclause = {init, STEP, PRED_F, FINI};
  74         Arrays.fill(clauses, clause);
  75         clauses[nClauses - 1] = fclause; // make the last clause terminate the loop
  76 
  77         try {
  78             MethodHandle loop = MethodHandles.loop(clauses);
  79             if (excessive) {
  80                 throw new AssertionError("loop construction should have failed");
  81             } else {
  82                 int r;
  83                 if (loopArgs == 0) {
  84                     r = (int) loop.invoke();
  85                 } else {
  86                     Object[] args = new Object[loopArgs];
  87                     Arrays.fill(args, 0);
  88                     r = (int) loop.invokeWithArguments(args);
  89                 }
  90                 System.out.println("SUCCEEDED (OK) -> " + r);
  91             }
  92         } catch (IllegalArgumentException iae) {
  93             if (excessive) {
  94                 System.out.println("FAILED    (OK)");
  95             } else {
  96                 iae.printStackTrace(System.out);
  97                 throw new AssertionError("loop construction should not have failed (see above)");
  98             }
  99         } catch (Throwable t) {
 100             t.printStackTrace(System.out);
 101             throw new AssertionError("unexpected failure (see above)");
 102         }
 103     }
 104 
 105 }