RFR [XS]: 8248429: Add --enable-preview as VM argument when running microbenchmarks

[Roger Riggs]

Hi,

I have found it very useful to be able to run benchmarks against multiple
versions of the JDK.  Build the benchmark jar once and to compare results.
If all of the classes are built with --enable-preview, none of them will 
run
against older JDKs. So an approach that only compiles those files that need
preview would be more useful.  Or perhaps, separate out preview based 
benchmarks
into a separate jar.

$.02, Roger


On 7/7/20 10:26 AM, Peter Levart wrote:
> I suggest adding --enable-preview to JMH_JVM_ARGS in general now (it 
> doesn't hurt even if classes are not compiled with --enable-preview) 
> and then take time to devise an effective strategy for selectively 
> compiling micro benchmarks with or without --enable-preview. At least 
> so the benchmarks would work out-of-the-box when run via make test.
>
> WDYT?
>
>
> Regards, Peter
>
>
> On 6/30/20 10:15 PM, Claes Redestad wrote:
>> On 2020-06-30 22:12, Magnus Ihse Bursie wrote:
>>>>
>>>> Second to that a solution in the build would be preferable - if we can
>>>> come up with something that has infinitesimal impact to build times.
>>> Are we talking about many files? Could you consider listing those 
>>> files explicitly in the makefile? That would make it cheap to filter 
>>> them out from the normal compilation, and instead do a secondary 
>>> compilation with them.
>>
>> Right now there's one micro using --enable-preview, so that'd be a very
>> short list.
>>
>> /Claes