test/tools/javac/lambda/LambdaConv03.java

Tue, 14 May 2013 11:11:09 -0700

author
rfield
date
Tue, 14 May 2013 11:11:09 -0700
changeset 1752
c09b7234cded
parent 0
959103a6100f
permissions
-rw-r--r--

8012556: Implement lambda methods on interfaces as static
8006140: Javac NPE compiling Lambda expression on initialization expression of static field in interface
Summary: Lambdas occurring in static contexts or those not needing instance information should be generated into static methods. This has long been the case for classes. However, as a work-around to the lack of support for statics on interfaces, interface lambda methods have been generated into default methods. For lambdas in interface static contexts (fields and static methods) this causes an NPE in javac because there is no 'this'. MethodHandles now support static methods on interfaces. This changeset allows lambda methods to be generated as static interface methods. An existing bug in Hotspot (8013875) is exposed in a test when the "-esa" flag is used. This test and another test that already exposed this bug have been marked with @ignore.
Reviewed-by: mcimadamore

     1 /*
     2  * Copyright (c) 2011, 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  */
    24 /*
    25  * @test
    26  * @bug 8003280
    27  * @summary Add lambda tests
    28  *  SAM types and method type inference
    29  * @author  Brian Goetz
    30  * @author  Maurizio Cimadamore
    31  * @run main LambdaConv03
    32  */
    34 public class LambdaConv03 {
    36     static int assertionCount = 0;
    38     static void assertTrue(boolean cond) {
    39         assertionCount++;
    40         if (!cond)
    41             throw new AssertionError();
    42     }
    44     interface TU<T, U> {
    45       public T foo(U u);
    46     }
    48     public static <T, U> T exec(TU<T, U> lambda, U x) {
    49         return lambda.foo(x);
    50     }
    52     static {
    53         //Covariant returns:
    54         int i1 = exec((Integer x) -> { return x; }, 3);
    55         assertTrue(3 == i1);
    56         //Method resolution with boxing:
    57         int i2 = exec((Integer x) -> { return x; }, 3);
    58         assertTrue(3 == i2);
    59         //Runtime exception transparency:
    60         try {
    61             exec((Object x) -> { return x.hashCode(); }, null);
    62         }
    63         catch (RuntimeException e) {
    64             assertTrue(true);
    65         }
    66     }
    68     {
    69         //Covariant returns:
    70         int i1 = exec((Integer x) -> { return x; }, 3);
    71         assertTrue(3 == i1);
    72         //Method resolution with boxing:
    73         int i2 = exec((Integer x) -> { return x; }, 3);
    74         assertTrue(3 == i2);
    75         //Runtime exception transparency:
    76         try {
    77             exec((Object x) -> { return x.hashCode(); }, null);
    78         }
    79         catch (RuntimeException e) {
    80             assertTrue(true);
    81         }
    82     }
    84     public static void test1() {
    85         //Covariant returns:
    86         int i1 = exec((Integer x) -> { return x; }, 3);
    87         assertTrue(3 == i1);
    88         //Method resolution with boxing:
    89         int i2 = exec((Integer x) -> { return x; }, 3);
    90         assertTrue(3 == i2);
    91         //Runtime exception transparency:
    92         try {
    93             exec((Object x) -> { return x.hashCode(); }, null);
    94         }
    95         catch (RuntimeException e) {
    96             assertTrue(true);
    97         }
    98     }
   100     public void test2() {
   101         //Covariant returns:
   102         int i1 = exec((Integer x) -> { return x; }, 3);
   103         assertTrue(3 == i1);
   104         //Method resolution with boxing:
   105         int i2 = exec((Integer x) -> { return x; }, 3);
   106         assertTrue(3 == i2);
   107         //Runtime exception transparency:
   108         try {
   109             exec((Object x) -> { return x.hashCode(); }, null);
   110         }
   111         catch (RuntimeException e) {
   112             assertTrue(true);
   113         }
   114     }
   116     public static void main(String[] args) {
   117         test1();
   118         new LambdaConv03().test2();
   119         assertTrue(assertionCount == 12);
   120     }
   121 }

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