RFR: 8338428: Add logging if final VM flags while setting properties [v5]

[Roger Riggs]

On Fri, 17 Jan 2025 15:59:50 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

>> Some VM flags might depend on the environment and it makes sense to log final flags so it is possible to get their value when investigating failures.
>> 
>> I added them to VMProps, so it is always dump final flags before running tests using "-XX:+PrintFlagsFinal".
>> 
>> Update:
>> There were intermittent compilation failures when I tried to use classes from testlibrary, so I rewrtite the code without them.
>
> Leonid Mesnik has updated the pull request incrementally with one additional commit since the last revision:
> 
>   copyrights updated

This seems like overkill for a weak use case.

The resulting log file is in the scratch directory so it will not be retained for long.
In local builds, whoever is running the test could add the arguments.

Have there been any negative interactions with any of the test tiers due to the addition of extra logging flags?

test/hotspot/jtreg/TEST.ROOT line 51:

> 49: requires.extraPropDefns.javacOpts = --add-exports java.base/jdk.internal.foreign=ALL-UNNAMED
> 50: requires.extraPropDefns.vmOpts = \
> 51:     -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput -XX:-DisplayVMOutput -XX:LogFile=vmprops.flags.final.vm.log \

The -XX:+UnlockDiagnosticVMOptions is repeated, that shouldn't be necessary. (in either TEST.ROOT)

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PR Review: https://git.openjdk.org/jdk/pull/23054#pullrequestreview-2559549496
PR Review Comment: https://git.openjdk.org/jdk/pull/23054#discussion_r1920505779