RFR: 8345259: Disallow ALL-MODULE-PATH without explicit --module-path [v8]

[Severin Gehwolf]

On Mon, 16 Dec 2024 19:07:51 GMT, Mandy Chung <mchung at openjdk.org> wrote:

>> jlink --add-modules ALL-MODULE-PATH --limit-modules jdk.jfr --module-path jmods --output all-mods-limit-mods.image
>> 
>> 
>> The set of observable modules only has `java.base` and `jdk.jfr` because of `--limit-modules`.   Hence `com.baz.runtime` from `jmods` is not observable.    `ALL-MODULE-PATH` adds all observable modules found on the relevant module paths are added to the root set.   This matches the run-time behavior.
>> 
>> 
>> $ java --list-modules -p com.baz.runtime.jar --add-modules ALL-MODULE-PATH --limit-modules jdk.jfr
>> java.base at 25-internal
>> jdk.jfr at 25-internal
>
> Limiting the observable modules is sometimes useful for testing/debugging and to reduce the number of modules resolved when the main module is the unnamed module.
> 
> @AlanBateman  Is `--limit-modules` needed at link time?

IMO it's also useful to limit included modules when `--bind-services` is being used.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22494#discussion_r1887479432