langtools/test/tools/javac/generics/wildcards/neg/CastWarn14.java
changeset 10 06bc494ca11e
child 2985 f43e1241e7fb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/wildcards/neg/CastWarn14.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,184 @@
+/*
+ * Copyright 2003 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 4916607
+ * @summary Test casts (legal, warning, and errors)
+ * @author gafter
+ *
+ * @compile/fail -source 1.5 -Werror -Xlint:unchecked CastWarn14.java
+ */
+
+import java.util.*;
+
+class CastTest {
+
+    // --- Directly transferring parameters ---
+
+    private class AA<T> { }
+
+    private class AB<T> extends AA<T> { }
+    private class AC<T> extends AA<Vector<T>> { }
+    private class AD<T> extends AA<Vector<? extends T>> { }
+    private class AE<T> extends AA<Vector<? super T>> { }
+    private class AF<T> extends AA<T[]> { }
+    private class AG<T> extends AA<String> { }
+
+    private void parameterTransfer() {
+        Object o;
+
+        o = (AB<String>) (AA<String>) null; // <<pass>>
+        o = (AB<String>) (AA<Number>) null; // <<fail 1>>
+        o = (AC<String>) (AA<Vector<String>>) null; // <<pass>>
+        o = (AC<String>) (AA<Vector<Number>>) null; // <<fail 2>>
+        o = (AC<String>) (AA<Stack<String>>) null; // <<fail 3>>
+
+        o = (AD<Number>) (AA<Vector<? extends Number>>) null; // <<pass>>
+        o = (AD<String>) (AA<Vector<? extends Number>>) null; // <<fail 4>>
+        o = (AD<?>) (AA<Vector<? extends Object>>) null; // <<pass>>
+        o = (AD<Object>) (AA<Vector<?>>) null; // <<pass>>
+
+        o = (AE<String>) (AA<Vector<? super String>>) null; // <<pass>>
+        o = (AE<Number>) (AA<Vector<? super String>>) null; // <<fail 5>>
+
+        o = (AF<String>) (AA<String[]>) null; // <<pass>>
+        o = (AF<String>) (AA<Number[]>) null; // <<fail 6>>
+
+        o = (AG<?>) (AA<String>) null; // <<pass>>
+        o = (AG<?>) (AA<Number>) null; // <<fail 7>>
+    }
+
+    // --- Inconsistent matches ---
+
+    private class BA<T> { }
+    private class BB<T, S> { }
+
+    private class BC<T> extends BA<Integer> { }
+    private class BD<T> extends BB<T, T> { }
+
+    private void inconsistentMatches() {
+        Object o;
+
+        o = (BC<?>) (BA<Integer>) null; // <<pass>>
+        o = (BC<?>) (BA<String>) null; // <<fail 8>>
+        o = (BD<String>) (BB<String, String>) null; // <<pass>>
+        o = (BD<String>) (BB<String, Number>) null; // <<fail 9>>
+        o = (BD<String>) (BB<Number, String>) null; // <<fail 10>>
+    }
+
+    private void whyMustEverythingBeSo_______Complicated() {
+        // This has to work...
+        BD<Number> bd = new BD<Number>();
+        BB<? extends Number, ? super Integer> bb = bd;
+        // 4916620: wildcards: legal cast is rejected
+        // bd = (BD<Number>) bb; // <<warn>> <<todo: cast-infer>>
+    }
+
+    // --- Transferring parameters via supertypes ---
+
+    private interface CA<T> { }
+    private interface CB<T> extends CA<T> { }
+    private interface CC<T> extends CA<T> { }
+
+    private class CD<T> implements CB<T> { }
+    private interface CE<T> extends CC<T> { }
+
+    private interface CF<S> { }
+    private interface CG<T> { }
+    private class CH<S, T> implements CF<S>, CG<T> { }
+    private interface CI<S> extends CF<S> { }
+    private interface CJ<T> extends CG<T> { }
+    private interface CK<S, T> extends CI<S>, CJ<T> { }
+
+    private void supertypeParameterTransfer() {
+        Object o;
+        CD<?> cd = (CE<?>) null; // <<fail 11>>
+        CE<?> ce = (CD<?>) null; // <<fail 12>>
+        o = (CE<String>) (CD<String>) null; // <<pass>>
+        o = (CE<Number>) (CD<String>) null; // <<fail 13>>
+
+        // 4916622: unnecessary warning with cast
+        // o = (CH<String, Integer>) (CK<String, Integer>) null; // <<pass>> <<todo: cast-infer>>
+    }
+
+    // --- Disjoint ---
+
+    private interface DA<T> { }
+    private interface DB<T> extends DA<T> { }
+    private interface DC<T> extends DA<Integer> { }
+
+    private <N extends Number, I extends Integer, R extends Runnable, S extends String> void disjointness() {
+        Object o;
+
+        // Classes
+        o = (DA<Number>) (DA<Integer>) null; // <<fail 14>>
+        o = (DA<? extends Number>) (DA<Integer>) null; // <<pass>>
+        o = (DA<? extends Integer>) (DA<Number>) null; // <<fail 15>>
+        o = (DA<? super Integer>) (DA<Number>) null; // <<pass>>
+        o = (DA<? super Number>) (DA<Integer>) null; // <<fail 16>>
+        o = (DA<?>) (DA<Integer>) null; // <<pass>>
+
+        o = (DA<? extends Runnable>) (DA<? extends Number>) null; // <<warn 2>>
+        o = (DA<? extends Runnable>) (DA<? extends String>) null; // <<fail 17>>
+
+        o = (DA<? super Integer>) (DA<? extends Number>) null; // <<warn 3>>
+        o = (DA<? super Number>) (DA<? extends Integer>) null; // <<fail 18>>
+        o = (DA<?>) (DA<? extends Integer>) null; // <<pass>>
+
+        o = (DA<? super String>) (DA<? super Number>) null; // <<warn 4>>
+        o = (DA<?>) (DA<? super String>) null; // <<pass>>
+
+        o = (DA<?>) (DA<?>) null; // <<pass>>
+
+        // Typevars
+        o = (DA<? extends Number>) (DA<I>) null; // <<pass>>
+        o = (DA<? extends Integer>) (DA<N>) null; // <<warn 5>>
+        o = (DA<? extends String>) (DA<I>) null; // <<fail 19>>
+
+        o = (DA<I>) (DA<? extends Number>) null; // <<warn 6>>
+        o = (DA<N>) (DA<? extends Integer>) null; // <<warn 7>>
+        o = (DA<N>) (DA<? extends Runnable>) null; // <<warn 8>>
+
+        o = (DA<N>) (DA<I>) null; // <<warn 9>>
+        o = (DA<N>) (DA<R>) null; // <<warn 10>>
+        o = (DA<S>) (DA<R>) null; // <<fail 20>>
+
+        // Raw (asymmetrical!)
+        o = (DA) (DB<Number>) null; // <<pass>>
+        o = (DA<Number>) (DB) null; // <<warn 11>>
+        o = (DA<?>) (DB) null; // <<pass>>
+        o = (DA<? extends Object>) (DB) null; // <<pass>>
+        o = (DA<? extends Number>) (DB) null; // <<warn 12>>
+
+        o = (DB) (DA<Number>) null; // <<pass>>
+        o = (DB<Number>) (DA) null; // <<warn 13>>
+        o = (DB<?>) (DA) null; // <<pass>>
+        o = (DB<? extends Object>) (DA) null; // <<pass>>
+        o = (DB<? extends Number>) (DA) null; // <<warn 14>>
+
+        o = (DC<?>) (DA<?>) null; // <<pass>>
+        o = (DC<?>) (DA<? super String>) null; // <<fail 21>>
+    }
+
+}