RFR: JDK-8046762, Revert some inference fixes in JDK-8033718

[Maurizio Cimadamore]

Looks good

Maurizio

On 13/06/14 18:23, Dan Smith wrote:
> This is a 8u20 patch to get type inference in a stable state.  It rolls back some changes in JDK-8033718 (and accompanying tests), rather than pushing forward with JDK-8039214 (which is the fix for 9).
>
> All existing tests pass, including the test added for related bug JDK-8042656 (IntersectionSubVar.java).
>
> —Dan
>
> # HG changeset patch
> # Parent e6d1e9f29132e71bd5d7095241e5fdb0223980bc
>
> diff -r e6d1e9f29132 src/share/classes/com/sun/tools/javac/code/Type.java
> --- a/src/share/classes/com/sun/tools/javac/code/Type.java	Tue Jun 10 15:25:01 2014 -0600
> +++ b/src/share/classes/com/sun/tools/javac/code/Type.java	Fri Jun 13 11:02:45 2014 -0600
> @@ -1658,9 +1658,6 @@
>                   //only change bounds if request comes from substBounds
>                   super.addBound(ib, bound, types, update);
>               }
> -            else if (bound.hasTag(UNDETVAR) && !((UndetVar) bound).isCaptured()) {
> -                ((UndetVar) bound).addBound(ib.complement(), this, types, false);
> -            }
>           }
>   
>           @Override
> diff -r e6d1e9f29132 src/share/classes/com/sun/tools/javac/code/Types.java
> --- a/src/share/classes/com/sun/tools/javac/code/Types.java	Tue Jun 10 15:25:01 2014 -0600
> +++ b/src/share/classes/com/sun/tools/javac/code/Types.java	Fri Jun 13 11:02:45 2014 -0600
> @@ -1396,7 +1396,7 @@
>   //                    debugContainsType(t, s);
>                       return isSameWildcard(t, s)
>                           || isCaptureOf(s, t)
> -                        || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) &&
> +                        || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), cvarLowerBound(wildLowerBound(s)))) &&
>                               // TODO: JDK-8039214, cvarUpperBound call here is incorrect
>                               (t.isSuperBound() || isSubtypeNoCapture(cvarUpperBound(wildUpperBound(s)), wildUpperBound(t))));
>                   }
> diff -r e6d1e9f29132 test/tools/javac/generics/inference/7086586/T7086586.out
> --- a/test/tools/javac/generics/inference/7086586/T7086586.out	Tue Jun 10 15:25:01 2014 -0600
> +++ b/test/tools/javac/generics/inference/7086586/T7086586.out	Fri Jun 13 11:02:45 2014 -0600
> @@ -1,5 +1,5 @@
> -T7086586.java:14:28: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: compiler.misc.type.captureof: 1, ?, java.lang.String)
> -T7086586.java:15:28: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: compiler.misc.type.captureof: 1, ?, java.lang.Number)
> -T7086586.java:16:31: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: compiler.misc.type.captureof: 1, ?, java.lang.Exception)
> -T7086586.java:17:13: compiler.err.cant.resolve.location.args: kindname.method, nonExistentMethod, , , (compiler.misc.location: kindname.interface, java.util.List<compiler.misc.type.captureof: 1, ?>, null)
> +T7086586.java:14:20: compiler.err.cant.apply.symbol: kindname.method, m, java.util.List<? super T>, java.util.List<compiler.misc.type.captureof: 1, ?>, kindname.class, T7086586, (compiler.misc.infer.no.conforming.assignment.exists: T, (compiler.misc.inconvertible.types: java.util.List<compiler.misc.type.captureof: 1, ?>, java.util.List<? super T>))
> +T7086586.java:15:20: compiler.err.cant.apply.symbol: kindname.method, m, java.util.List<? super T>, java.util.List<compiler.misc.type.captureof: 1, ?>, kindname.class, T7086586, (compiler.misc.infer.no.conforming.assignment.exists: T, (compiler.misc.inconvertible.types: java.util.List<compiler.misc.type.captureof: 1, ?>, java.util.List<? super T>))
> +T7086586.java:16:23: compiler.err.cant.apply.symbol: kindname.method, m, java.util.List<? super T>, java.util.List<compiler.misc.type.captureof: 1, ?>, kindname.class, T7086586, (compiler.misc.infer.no.conforming.assignment.exists: T, (compiler.misc.inconvertible.types: java.util.List<compiler.misc.type.captureof: 1, ?>, java.util.List<? super T>))
> +T7086586.java:17:9: compiler.err.cant.apply.symbol: kindname.method, m, java.util.List<? super T>, java.util.List<compiler.misc.type.captureof: 1, ?>, kindname.class, T7086586, (compiler.misc.infer.no.conforming.assignment.exists: T, (compiler.misc.inconvertible.types: java.util.List<compiler.misc.type.captureof: 1, ?>, java.util.List<? super T>))
>   4 errors
> diff -r e6d1e9f29132 test/tools/javac/generics/inference/7086586/T7086586b.java
> --- a/test/tools/javac/generics/inference/7086586/T7086586b.java	Tue Jun 10 15:25:01 2014 -0600
> +++ b/test/tools/javac/generics/inference/7086586/T7086586b.java	Fri Jun 13 11:02:45 2014 -0600
> @@ -23,10 +23,9 @@
>   
>   /*
>    * @test
> - * @bug 7086586 8033718
> + * @bug 7086586
>    *
> - * @summary Inference producing null type argument; inference ignores capture
> - *          variable as upper bound
> + * @summary Inference producing null type argument
>    */
>   import java.util.List;
>   
> @@ -41,8 +40,8 @@
>           assertionCount++;
>       }
>   
> -    <T> void m(List<? super T> dummy) { assertTrue(true); }
> -    <T> void m(Object dummy) { assertTrue(false); }
> +    <T> void m(List<? super T> dummy) { assertTrue(false); }
> +    <T> void m(Object dummy) { assertTrue(true); }
>   
>       void test(List<?> l) {
>           m(l);
> diff -r e6d1e9f29132 test/tools/javac/generics/inference/NestedWildcards.java
> --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
> +++ b/test/tools/javac/generics/inference/NestedWildcards.java	Fri Jun 13 11:02:45 2014 -0600
> @@ -0,0 +1,44 @@
> +/*
> + * Copyright (c) 2014, 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 8046762
> + * @summary Nested generic methods that work on wildcard-parameterized types
> + * @compile NestedWildcards.java
> + */
> +
> +public class NestedWildcards {
> +
> +    public static void test(Box<String> b) {
> +        foo(bar(b));
> +    }
> +    private static <X> Box<? extends X> foo(Box<? extends X> ts) {
> +        return null;
> +    }
> +    public static <Y> Box<? extends Y> bar(Box<? extends Y> language) {
> +        return null;
> +    }
> +
> +    interface Box<T> {}
> +}
>