1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/test/tools/javac/generics/wildcards/pos/CastTest.java Wed Apr 27 01:34:52 2016 +0800
1.3 @@ -0,0 +1,149 @@
1.4 +/*
1.5 + * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + */
1.26 +
1.27 +/*
1.28 + * @test
1.29 + * @bug 4916607
1.30 + * @summary Test casts (legal, warning, and errors)
1.31 + * @author gafter
1.32 + *
1.33 + * @compile -Werror CastTest.java
1.34 + */
1.35 +
1.36 +import java.util.*;
1.37 +
1.38 +class CastTest {
1.39 +
1.40 + // --- Directly transferring parameters ---
1.41 +
1.42 + private class AA<T> { }
1.43 +
1.44 + private class AB<T> extends AA<T> { }
1.45 + private class AC<T> extends AA<Vector<T>> { }
1.46 + private class AD<T> extends AA<Vector<? extends T>> { }
1.47 + private class AE<T> extends AA<Vector<? super T>> { }
1.48 + private class AF<T> extends AA<T[]> { }
1.49 + private class AG<T> extends AA<String> { }
1.50 +
1.51 + private void parameterTransfer() {
1.52 + Object o;
1.53 +
1.54 + o = (AB<String>) (AA<String>) null; // <<pass>>
1.55 + o = (AC<String>) (AA<Vector<String>>) null; // <<pass>>
1.56 +
1.57 + o = (AD<Number>) (AA<Vector<? extends Number>>) null; // <<pass>>
1.58 + o = (AD<?>) (AA<Vector<? extends Object>>) null; // <<pass>>
1.59 + o = (AD<Object>) (AA<Vector<?>>) null; // <<pass>>
1.60 +
1.61 + o = (AE<String>) (AA<Vector<? super String>>) null; // <<pass>>
1.62 +
1.63 + o = (AF<String>) (AA<String[]>) null; // <<pass>>
1.64 +
1.65 + o = (AG<?>) (AA<String>) null; // <<pass>>
1.66 + }
1.67 +
1.68 + // --- Inconsistent matches ---
1.69 +
1.70 + private class BA<T> { }
1.71 + private class BB<T, S> { }
1.72 +
1.73 + private class BC<T> extends BA<Integer> { }
1.74 + private class BD<T> extends BB<T, T> { }
1.75 +
1.76 + private void inconsistentMatches() {
1.77 + Object o;
1.78 +
1.79 + o = (BC<?>) (BA<Integer>) null; // <<pass>>
1.80 + o = (BD<String>) (BB<String, String>) null; // <<pass>>
1.81 + }
1.82 +
1.83 + private void whyMustEverythingBeSo_______Complicated() {
1.84 + // This has to work...
1.85 + BD<Number> bd = new BD<Number>();
1.86 + BB<? extends Number, ? super Integer> bb = bd;
1.87 +
1.88 + // 4916620: wildcards: legal cast is rejected
1.89 + // bd = (BD<Number>) bb; // <<warn>> <<todo: cast-infer>>
1.90 + }
1.91 +
1.92 + // --- Transferring parameters via supertypes ---
1.93 +
1.94 + private interface CA<T> { }
1.95 + private interface CB<T> extends CA<T> { }
1.96 + private interface CC<T> extends CA<T> { }
1.97 +
1.98 + private class CD<T> implements CB<T> { }
1.99 + private interface CE<T> extends CC<T> { }
1.100 +
1.101 + private interface CF<S> { }
1.102 + private interface CG<T> { }
1.103 + private class CH<S, T> implements CF<S>, CG<T> { }
1.104 + private interface CI<S> extends CF<S> { }
1.105 + private interface CJ<T> extends CG<T> { }
1.106 + private interface CK<S, T> extends CI<S>, CJ<T> { }
1.107 +
1.108 + private void supertypeParameterTransfer() {
1.109 + Object o;
1.110 + o = (CE<String>) (CD<String>) null; // <<pass>>
1.111 +
1.112 + // 4916622: unnecessary warning with cast
1.113 + // o = (CH<String, Integer>) (CK<String, Integer>) null; // <<pass>> <<todo: cast-infer>>
1.114 + }
1.115 +
1.116 + // --- Disjoint ---
1.117 +
1.118 + private interface DA<T> { }
1.119 + private interface DB<T> extends DA<T> { }
1.120 + private interface DC<T> extends DA<Integer> { }
1.121 +
1.122 + private <N extends Number, I extends Integer, R extends Runnable, S extends String> void disjointness() {
1.123 + Object o;
1.124 +
1.125 + // Classes
1.126 + o = (DA<? extends Number>) (DA<Integer>) null; // <<pass>>
1.127 + o = (DA<? super Integer>) (DA<Number>) null; // <<pass>>
1.128 + o = (DA<?>) (DA<Integer>) null; // <<pass>>
1.129 +
1.130 + o = (DA<?>) (DA<? extends Integer>) null; // <<pass>>
1.131 +
1.132 + o = (DA<?>) (DA<? super String>) null; // <<pass>>
1.133 +
1.134 + o = (DA<?>) (DA<?>) null; // <<pass>>
1.135 +
1.136 + // Typevars
1.137 + o = (DA<? extends Number>) (DA<I>) null; // <<pass>>
1.138 +
1.139 + // Raw (asymmetrical!)
1.140 + o = (DA) (DB<Number>) null; // <<pass>>
1.141 + o = (DA<?>) (DB) null; // <<pass>>
1.142 + o = (DA<? extends Object>) (DB) null; // <<pass>>
1.143 +
1.144 + o = (DB) (DA<Number>) null; // <<pass>>
1.145 + o = (DB<?>) (DA) null; // <<pass>>
1.146 + o = (DB<? extends Object>) (DA) null; // <<pass>>
1.147 +
1.148 + // reported broken (5034609)
1.149 + // o = (DC<?>) (DA<?>) null; // <<pass>>
1.150 + }
1.151 +
1.152 +}
