8332074: Create a "jdk.exploded" test property to check if the testee jdk is exploded

[tstuefe]

Since we cannot run CDS operations on an exploded JDK, excluding tests like these for exploded JDKs makes sense.

However, being an exploded JDK is not the same as not having CDS built into the JVM. Plus, exploded JDKs have effects beyond their inability to run with CDS. Therefore a property makes sense.

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• JDK-8332074: Create a "jdk.exploded" test property to check if the testee jdk is exploded (Enhancement - P4)

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[AlanBateman]

This looks useful. I just wonder about the terminology. We usually speak of an exploded image or exploded build, just reacting to the name and the comment that it checks "whether the test JDK is exploded".

[magicus]

There is a long standing build infra bug about changing "JDK exploded". First of all, the name is not at all fitting for what it really is, so the proposal is to rename it to a "partial JDK". Secondly, there are different opinions on what should be included in a partial JDK, so the concept might be expanded to allow for building different kinds of partial JDKs with different amount of functionality present.

I did a quick search but could not find the associated JBS issue, but it is there somewhere.

[magicus]

This also means that I think the solution you did in JDK-8332105 is superior to this, where you test for the individual functionality you want. Adding a broad "jdk exploded" property to the tests will only complicate matters if/when we support multiple kinds of partial JDKs.