ExceptionInInitializerError when using jdk.nashorn.internal.ir.debug.ObjectSizeCalculator.getObjectSize(object) on OpenJDK VM

[张同宝(井桐)]

Hi all,

We get the ExceptionInInitializerError when using the method jdk.nashorn.internal.ir.debug.ObjectSizeCalculator.getObjectSize on our openjdk build. the exception message says "ObjectSizeCalculator only supported on HotSpot VM".
After check the source code, we find the exception was throwed by method getEffectiveMemoryLayoutSpecification:the code is:    final String vmName = System.getProperty("java.vm.name"); 
                      if (vmName == null || !vmName.startsWith("OpenJDK"))   throw new UnsupportedOperationException() here is the source code:http://hg.openjdk.java.net/jdk8u/jdk8u/nashorn/file/91d33aea2714/src/jdk/nashorn/internal/ir/debug/ObjectSizeCalculator.java#l397 , and the current jdk9 nashorn source code remains the same: http://hg.openjdk.java.net/jdk9/jdk9/nashorn/file/a9c819c3c7f6/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/debug/ObjectSizeCalculator.java#l397 

Since we are building jdk in the openjdk repo and the build's system property "java.vm.name" starts with "OpenJDK" (e.g., "OpenJDK 64-Bit Server VM"), we are considering maybe this code can be changed to !vmName.startsWith("OpenJDK"), and the exception message should also be changed to "ObjectSizeCalculator only supported on OpenJDK VM"
Thanks,Tongbao Zhang from Alibaba