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

[Kim Barrett]

On Sat, 29 Mar 2025 02:47:53 GMT, Calvin Cheung <ccheung 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.

test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/DynamicArchiveRelocationTest.java line 48:

> 46:     static int relocationMode = -1;
> 47:     public static void main(String... args) throws Exception {
> 48:         WhiteBox wb = WhiteBox.getWhiteBox();

It seems this test already had WhiteBox enabled, but wasn't actually using it before this change.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24308#discussion_r2020040853
PR Review Comment: https://git.openjdk.org/jdk/pull/24308#discussion_r2020041231