[lworld] RFR: 8374025: [lworld] valhalla/valuetypes/SubstitutabilityTest.java fails due to argument clashes [v2]

[Roger Riggs]

On Thu, 29 Jan 2026 16:35:25 GMT, Paul Hübner <phubner at openjdk.org> wrote:

>> Hi all,
>> 
>> Currently, the non-CDS test of `valhalla/valuetypes/SubstitutabilityTest.java` is disabled. This is because it uses `-Xshare:off` which is fundamentally incompatible with some AOT flags that the test is run with.
>> 
>> In this fix, we introduce a new `@requires` property which denotes if the AOT code cache has been given as a command-line argument. If that is the case, we skip the test. For context, from the failure:
>>> Option AOTCache cannot be used at the same time with -Xshare:on, -Xshare:auto, -Xshare:off, -Xshare:dump, DumpLoadedClassList, SharedClassListFile, or SharedArchiveFile
>> 
>> An alternative considered was to use `@requires vm.flagless`. However, there are many configurations, such as different GCs, that we would lose out on. Substitutability plays quite a central concept with value classes, therefore, a new property is perhaps the more suitable approach.
>> 
>> Testing: the Oracle tiers in which we observed failures, and a smoke-test tier 1 on Linux (x64, AArch64), macOS (x64, AArch64), Windows (x64).
>
> Paul Hübner has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Merge and don't share.
>  - Revert "Restrain SubstitutabilityTest with -Xshare:off."
>    
>    This reverts commit 0fc69eb72574f32b802fdf0a06ecc46fb0fcf3e2.

Looks good and simpler.

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Marked as reviewed by rriggs (Committer).

PR Review: https://git.openjdk.org/valhalla/pull/1995#pullrequestreview-3724439954