Configure: Does enabling graal automatically disable cmsgc?

[Magnus Ihse Bursie]

On 2018-08-31 11:39, Lindenmaier, Goetz wrote:
> Hi,
>
> I'm just fixing jtreg/runtime/appcds/sharedStrings/IncompatibleOptions.java
>
> It is not checking correctly whether ZGC is enabled.
>
> I found this code in the test:
> if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
>        testExec(8, "-XX:+UseConcMarkSweepGC", "", "", false);
> }
>
> I think this should test for GC.CMS.isSupported(). I would like to
> fix this, too.
> But this would require that configuring with graal disables cmsgc.
> (Which seems to be what is desired given the comment above.)
> Is this the case?

Maybe I'm confused here, but are you not mixing up configure options and 
run-time options? Both graal and CMS require run-time options to be 
enabled, right? So it's an error to enable both of them. But that does 
not prohibit you to build a JVM that has support for both Graal and CMS 
(as long as you only enable at most one of them at a time).

/Magnus