8166363: Method with reordered type parameter bounds compiles with @Override annotation but does not actually override superclass method.
authorsadayapalam
Wed, 28 Sep 2016 09:05:20 +0530
changeset 41247 002eb49496ca
parent 41167 d273dfe9a126
child 41248 2a3e74c5ad8a
8166363: Method with reordered type parameter bounds compiles with @Override annotation but does not actually override superclass method. Reviewed-by: vromero
langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransTypes.java
langtools/test/tools/javac/generics/bridges/ReorderedBoundsTest.java
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransTypes.java	Wed Jul 05 22:16:18 2017 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransTypes.java	Wed Sep 28 09:05:20 2016 +0530
@@ -415,10 +415,10 @@
                 if (!isSameMemberWhenErased(dest, impl, impl_erasure))
                     return true;
 
-                // If the erasure of the return type is different, a
-                // bridge is needed.
-                return !types.isSameType(impl_erasure.getReturnType(),
-                                         method_erasure.getReturnType());
+                /* Bottom line: A bridge is needed if the erasure of the implementation
+                   is different from that of the method that it overrides.
+                */
+                return !types.isSameType(impl_erasure, method_erasure);
             } else {
                // method and impl are the same...
                 if ((method.flags() & ABSTRACT) != 0) {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/bridges/ReorderedBoundsTest.java	Wed Sep 28 09:05:20 2016 +0530
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8166363
+ * @summary Method with reordered type parameter bounds compiles with Override annotation but does not actually override superclass method.
+ * @run main ReorderedBoundsTest
+ */
+
+import java.io.Serializable;
+
+public class ReorderedBoundsTest {
+  public static class Parent {
+    public <T extends Appendable & Serializable> String printClassName(T t) {
+      return "Parent";
+    }
+  }
+
+  public static class OrderedChild extends Parent {
+    @Override
+    public <T extends Appendable & Serializable> String printClassName(T t) {
+      return "OrderedChild";
+    }
+  }
+
+  public static class ReorderedChild extends Parent {
+    @Override
+    public <T extends Serializable & Appendable> String printClassName(T t) {
+      return "ReorderedChild";
+    }
+  }
+
+  public static void main(String[] args) {
+
+    String s;
+    Parent p = new OrderedChild();
+    if (!(s = p.printClassName(new StringBuilder())).equals("OrderedChild"))
+        throw new AssertionError("Bad output: " + s);
+
+    p = new ReorderedChild();
+    if (!(s = p.printClassName(new StringBuilder())).equals("ReorderedChild"))
+        throw new AssertionError("Bad output: " + s);
+  }
+}
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