Change for 8248135: Build microbenchmarks with --enable-preview makes other non-preview JMH benchmarks to fail

[Peter Levart]

On 7/7/20 10:13 AM, David Holmes wrote:
> Hi Peter,
>
> cc Claes
>
> On 7/07/2020 5:59 pm, Peter Levart wrote:
>> Hi,
>>
>>
>> Recently I proposed and pushed a change for [1] which adds 
>> --enable-preview option to javac compilation of JMH microbenchmarks 
>> in general to enable running a benchmark that uses preview feature 
>> (Records). This makes the class files produced marked with version 
>> 60.65535. The benchmark that uses preview feature executes without 
>> problems because it explicitly specifies the following in its code:
>>
>>
>> @Fork(value = 1, warmups = 0, jvmArgsAppend = "--enable-preview")
>>
>>
>> Recently I wanted to run JMH benchmarks for Stream ops with:
>>
>>
>> make test TEST="micro:java.util.stream.ops"
>>
>>
>> ...but all of them fail to run with the following exception:
>>
>>
>> java.lang.UnsupportedClassVersionError: Preview features are not 
>> enabled for 
>> org/openjdk/bench/java/util/stream/ops/value/generated/NoneMatchShort_seq_start_jmhTest 
>> (class file version 60.65535). Try running with '--enable-preview'
>>
>>
>> What shall we do? Add similar annotation to all of them? Is there a 
>> way to specify that all micro benchmarks should be run with 
>> --enable-preview option passed to java?
>
> So this breaks running all non-preview using benchmarks? If so I say 
> we need to backout the change for 8248135 while a proper solution is 
> found.


I guess it does break (at least the way I tried to run them). The 
problem is that this little change:


--- a/make/test/BuildMicrobenchmark.gmk    Wed Jun 24 01:02:19 2020 +0200
+++ b/make/test/BuildMicrobenchmark.gmk    Wed Jun 24 11:05:09 2020 +0200
@@ -90,10 +90,11 @@
      TARGET_RELEASE := $(TARGET_RELEASE_NEWJDK_UPGRADED), \
      SMALL_JAVA := false, \
      CLASSPATH := $(MICROBENCHMARK_CLASSPATH), \
-    DISABLED_WARNINGS := processing rawtypes cast serial, \
+    DISABLED_WARNINGS := processing rawtypes cast serial preview, \
      SRC := $(MICROBENCHMARK_SRC), \
      BIN := $(MICROBENCHMARK_CLASSES), \
      JAVA_FLAGS := --add-modules jdk.unsupported --limit-modules 
java.management, \
+    JAVAC_FLAGS := --enable-preview, \
  ))


...was pushed as part of larger fix for 8247532 which has already been 
forward and backported. So I think backing out the whole patch (which is 
perfectly OK by itself) would cause more problems then fixing this 
particular problem in a followup, given that we can find a fix quickly. 
Its has been 14 days since the above was pushed and nobody noticed until 
now, so I guess this is not a big problem?


Regards, Peter



>
> David
> -----
>
>>
>> [1] https://bugs.openjdk.java.net/browse/JDK-8248135
>>
>>
>> Regards, Peter
>>
>>