RFR: 8353129: CDS ArchiveRelocation tests fail after JDK-8325132

[David Holmes]

On Sun, 30 Mar 2025 01:05:48 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Two archive relocation tests failed when `-XX:ArchiveRelocationMode=0` is specified via the jtreg `-javaoption`.
>> A fix is to add a `WhiteBox.getArchiveRelocationMode()` method so that the tests can check if the `ArchiveRelocationMode` is set to 0 before checking the expected output.
>> 
>> Passed tiers 1 - 4 testing.
>
> src/hotspot/share/prims/whitebox.cpp line 2139:
> 
>> 2137: #else
>> 2138:   ShouldNotReachHere();
>> 2139:   return (jint)-1;
> 
> Unnecessary dead code.  Or maybe this shouldn't be using `ShouldNotReachHere()`. Is the intent
> to crash in a debug build but return an error code in a product build?  If so, `ShouldNotReachHere()`
> doesn't provide that behavior, as it affects product builds too.

I think the intent is to crash if someone runs a test that uses CDS and this API in a build without CDS available. You literally should not reach here as the test should have been skipped at a higher level -  that is true for debug and product test runs.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24308#discussion_r2020303022