Name: rmT116609 Date: 08/07/2003


FULL PRODUCT VERSION :
java version "1.4.2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-b28)
Java HotSpot(TM) Client VM (build 1.4.2-b28, mixed mode)

FULL OS VERSION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
I compiled the included test case code in javac, using the following compiler options:

-J-Djava.endorsed.dirs=.
-Xswitchcheck
-deprecation
-d bin
-target 1.1

looking at the javap disassembly, the exception table lists the target line at being within the exception range (try block) that it is itself handling.

This is causing a lock-up in at least one JVM implementation that I have to support. I have compared the javac output with other 3rd party compiler implementations and they do not generate a target within the exception range. Consequently, they work with all of our targeted JVM's. As far as I can tell, older versions of javac did not produce this problem either.

As a result, I cannot use javac for release builds of our product. I was hoping to migrate from the MS jvc compiler!

I have consulted with people who know the JVM spec in more detail than myself, and they suggested that this behaviour was unexpected.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
--- javap disassembly of eclipse generated class ---
public class com.m_systems.api.test.MSJVMSyncExcLockupTestApp extends java.lang.Object{
public com.m_systems.api.test.MSJVMSyncExcLockupTestApp();
  Code:
   0: aload_0
   1: invokespecial #9; //Method java/lang/Object."<init>":()V
   4: return


public static void main(java.lang.String[]);
  Code:
   0: new #17; //class Integer
   3: dup
   4: bipush 6
   6: invokespecial #20; //Method java/lang/Integer."<init>":(I)V
   9: astore_1
   10: aload_1
   11: dup
   12: astore_2
   13: monitorenter
   14: new #22; //class NullPointerException
   17: dup
   18: invokespecial #23; //Method java/lang/NullPointerException."<init>":()V
   21: athrow
   22: aload_2
   23: monitorexit
   24: athrow
  Exception table:
   from to target type
    14 22 22 any
}
ACTUAL -
--- javap disassembly of javac generated class ---
public class com.m_systems.api.test.MSJVMSyncExcLockupTestApp extends java.lang.Object{
public com.m_systems.api.test.MSJVMSyncExcLockupTestApp();
  Code:
   0: aload_0
   1: invokespecial #1; //Method java/lang/Object."<init>":()V
   4: return


public static void main(java.lang.String[]);
  Code:
   0: new #2; //class Integer
   3: dup
   4: bipush 6
   6: invokespecial #3; //Method java/lang/Integer."<init>":(I)V
   9: astore_1
   10: aload_1
   11: dup
   12: astore_2
   13: monitorenter
   14: new #4; //class NullPointerException
   17: dup
   18: invokespecial #5; //Method java/lang/NullPointerException."<init>":()V
   21: athrow
   22: astore_3
   23: aload_2
   24: monitorexit
   25: aload_3
   26: athrow
  Exception table:
   from to target type
    14 25 22 any
}


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class JVMSyncExcLockupTestApp {
   public static void main(String[] args){
      Integer i = new Integer(6);
      synchronized (i){
         if (true){
            throw new NullPointerException();
         }
      }
   }
}

---------- END SOURCE ----------
(Incident Review ID: 194022)
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