RFR: 8263399: CDS should archive only classes allowed by module system [v2]

[Calvin Cheung]

On Thu, 11 Mar 2021 20:20:32 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> `ClassListParser::load_current_class()` tries to archive a boot class from `-Xbootclasspath/a` into the unnamed package, even if the module system forbids this class from being defined in the unnamed package.
>> 
>> Such classes, even if archived, won't be usable at runtime anyway. The only test case affected by this code is test/hotspot/jtreg/runtime/cds/appcds/jigsaw/classpathtests/BootAppendTests.java, which asserts that such class must be archived, but also asserts that such archived classes cannot be used at runtime. So the first assert seems unnecessary and should be removed.
>> 
>> The main change is in classListParser.cpp.
>> 
>> The change in metaspaceShared.cpp is necessary because the `Preload Warning: Cannot find %s"` message was sometimes printed only in the code path that I've deleted.
>
> Ioi Lam has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - improved comments per @calvinccheung review
>  - Merge branch 'master' of https://github.com/openjdk/jdk into 8263399-archive-only-classes-allowed-by-modules
>  - 8263399: CDS should archive only classes allowed by module system

Marked as reviewed by ccheung (Reviewer).

-------------

PR: https://git.openjdk.java.net/jdk/pull/2929