8157947: SA: Javascript engine can't access internal packages of jdk.hotspot.agent

[Yasumasa Suenaga]

Hi all,

I saw the message when I attached CLHSDB to target VM as below:

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javax.script.ScriptException: TypeError: sapkg.runtime.VM.getVM is not a function in sa.js at line number 54
Warning! JS Engine can't start, some commands will not be available.
----

It has been reported as JDK-8157947.


It is caused that jdk.hotspot.agent module is not exported to
nashorn dynamic module.
The comment in JDK-8157947 says that it will be fixed if we implement
JSObject, but I think it is difficult because we cannot know
what classes in SA are used in user scripts.

So I think two approaches for this issue:


   1. Open all packages in module-info in jdk.hotspot.agent
        I filed suggested fix to JBS, but it is not smart...

   2. Open all packages in JSJavaScriptEngine::<clinit>
        Opens all packages to Module.EVERYONE_MODULE.
        But EVERYONE_MODULE is private field, so we need to access
        from JNI code.
          http://cr.openjdk.java.net/~ysuenaga/JDK-8157947/proposal/
        This change has passed serviceability/sa jtreg tests.


Both ideas is hackish, but I prefer to 2. to fix it.
If 2. is accepted I will push it to submit repo and send review request.

What do you think?


Thanks,

Yasumasa