RFR: 8307508: IndirectVarHandle.isAccessModeSupported throws NPE

[Mandy Chung]

On Mon, 12 Jun 2023 05:27:35 GMT, Chen Liang <liach at openjdk.org> wrote:

> Fixes the NPE in IndirectVarHandle.isAccessModeSupported by delegating to the target var handle. In addition, simplified the MH caching in Indirect VH and removed redundant overrides (already available via var form). This was split from #13821 as suggested by Mandy Chung, which allows easy backports to release 21 if desirable.

The fix looks good.  Also nice clean up.

test/jdk/java/lang/invoke/VarHandles/IndirectVarHandleTest.java line 28:

> 26:  * @summary tests for IndirectVarHandle
> 27:  * @compile --enable-preview --release 22 IndirectVarHandleTest.java
> 28:  * @run junit/othervm --enable-preview IndirectVarHandleTest

Suggestion:

 * @enablePreview
 * @run junit IndirectVarHandleTest
 * @summary Test VarHandle::isAccessModeSupported on indirect VarHandle produced by MethodHandles.filterCoordinates


Should simply use jtreg `@enablePreview`.    Suggest to move `@summary` to the end and also can be more specific.

test/jdk/java/lang/invoke/VarHandles/IndirectVarHandleTest.java line 44:

> 42:         var lookup = MethodHandles.lookup();
> 43:         var intArrayVh = MethodHandles.arrayElementVarHandle(int[].class);
> 44:         var addOne = lookup.bind((IntUnaryOperator) a -> a + 1, "applyAsInt", MethodType.methodType(int.class, int.class));

Nit: a couple of long lines (L44, 48 and 55) can be wrapped into separate line.

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Marked as reviewed by mchung (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14409#pullrequestreview-1475930012
PR Review Comment: https://git.openjdk.org/jdk/pull/14409#discussion_r1227316722
PR Review Comment: https://git.openjdk.org/jdk/pull/14409#discussion_r1227319788