RFR: 8345259: Disallow ALL-MODULE-PATH without explicit --module-path [v11]

[Mandy Chung]

On Tue, 17 Dec 2024 11:45:56 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

>> Please review this extension to #22609 which now disallows `ALL-MODULE-PATH` without explicit `--module-path` option or a non-existent module path. In addition, this fixes a bug mentioned in #22609 when `ALL-MODULE-PATH` and `--limit-modules` are used in combination. It failed earlier and passes now due to alignment of `ModuleFinder`s. With this patch JEP 493 enabled builds and regular JDK builds behave the same in terms of `ALL-MODULE-PATH`.
>> 
>> When an explicit module path is being added, there is no difference. All modules on that path will be added as roots. Tests have been added for the various cases and existing tests updated to allow for them to run on JEP 493 enabled builds. Thoughts?
>> 
>> Testing:
>> - [x] GHA, `test/jdk/tools/jlink` (all pass)
>> - [x] Added jlink test.
>
> Severin Gehwolf has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix comments

$ jlink --add-modules ALL-MODULE-PATH --module-path build/jmods --limit-modules jdk.net --output ./build/test-img


This creates an image with jdk.net and its transitive dependences which is the existing behavior, right?  We are trying to revisit `--add-modules ALL-MODULE-PATH` with `--limit-modules` in the future. 

> "transitive closure of named modules plus the modules added with --add-modules" as {java.base, a, b, c}

Yes.  That's how it is implemented as  https://openjdk.org/jeps/261#Limiting-the-observable-modules describes:

> (The transitive closure computed for the interpretation of the --limit-modules option is a temporary result, used only to compute the limited set of observable modules. The resolver will be invoked again in order to compute the actual module graph.)

So jlink sets up the finder that limits the observability and compute the module graph from the roots using this finder.

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PR Comment: https://git.openjdk.org/jdk/pull/22494#issuecomment-2551955652