Hello,
Please review this simple change for improving diagnostics around class
verification and linking failures:
Bug: https://bugs.openjdk.java.net/browse/JDK-8243290
Webrev: http://cr.openjdk.java.net/~poonam/8243290/webrev.00/
Problem: During the class redefinition process, if a class verification
fails because it could not find a class referenced in the class being
redefined, the printed NoClassDefFoundError error message is not very
helpful. It does not print the class name for which NoClassDefFoundError
was encountered, and that makes it very hard to find the real cause of
redefinition failure.
The proposed solution prints the class name during class linking and
verification failures. Example output produced with these changes:
With 'redefine' tag:
[java] [3.243s][debug][redefine,class,load ] loaded
name=org.apache.commons.logging.impl.Jdk14Logger (avail_mem=819540K)
[java] [3.243s][debug][redefine,class,load ] loading
name=org.apache.commons.logging.impl.Log4JLogger kind=101 (avail_mem=819540K)
[java] [3.244s][info ][redefine,class,load,exceptions] link_class
exception: 'java/lang/NoClassDefFoundError org/apache/log4j/Priority'
[java] Java Result: 1
With 'verification' tag:
[java] [49.702s][info ][verification] Verification for
org.apache.commons.logging.impl.Log4JLogger has exception pending
'java.lang.NoClassDefFoundError org/apache/log4j/Priority'
[java] [49.702s][info ][verification] End class verification for:
org.apache.commons.logging.impl.Log4JLogger
Improved error message:
[java] Exception in thread "main" java.lang.InternalError: class
redefinition failed: invalid class
[java] at
java.instrument/sun.instrument.InstrumentationImpl.retransformClasses0(Native
Method)
[java] at
java.instrument/sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:167)
[java] at Main.main(Unknown Source)
Thanks,
Poonam
