Name: skT45625 Date: 11/27/2000


java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)

I believe this problem is similar to bug #4285499.

Compile the following test program using this command line:

javac -target 1.3 -g BugTest

Then run the program like this:

java BugTest

Which should cause the following output:

java.lang.AbstractMethodError
        at BugTest.runTest(BugTest.java:13)
        at BugTest.main(BugTest.java:5)

Now compile like this:

javac -target 1.1 -g BugTest.java

and rerun the program to obtain this output:

Success

Using the javap tool you can see that at instruction #11 there is a difference
between the target 1.3 and target 1.1 code. I take this to indicate a code
generation problem, but I suppose it could be a problem with the JVM if the
instruction at #11 is really correct code.

Code from -target 1.3:

Method void runTest()
   0 new #5 <Class BugTest. Test>
   3 dup
   4 aload_0
   5 aconst_null
   6 invokespecial #6 <Method BugTest. Test(BugTest,BugTest$1)>
   9 astore_1
  10 aload_1
  11 invokeinterface (args 1) #7 <InterfaceMethod null>
  16 checkcast #8 <Interface BugTest. Interface2>
  19 astore_2
  20 getstatic #9 <Field java.io.PrintStream out>
  23 ldc #10 <String "Success">
  25 invokevirtual #11 <Method void println(java.lang.String)>
  28 goto 36
  31 astore_1
  32 aload_1
  33 invokevirtual #13 <Method void printStackTrace()>
  36 return

Code from -target 1.1:

Method void runTest()
   0 new #5 <Class BugTest. Test>
   3 dup
   4 aload_0
   5 aconst_null
   6 invokespecial #6 <Method BugTest. Test(BugTest,BugTest$1)>
   9 astore_1
  10 aload_1
  11 invokeinterface (args 1) #7 <InterfaceMethod java.lang.Object clone()>
  16 checkcast #8 <Interface BugTest. Interface2>
  19 astore_2
  20 getstatic #9 <Field java.io.PrintStream out>
  23 ldc #10 <String "Success">
  25 invokevirtual #11 <Method void println(java.lang.String)>
  28 goto 36
  31 astore_1
  32 aload_1
  33 invokevirtual #13 <Method void printStackTrace()>
  36 return

Here is the program:
//--------Program follows-----------------
public class BugTest
{
    public static void main( String[] args )
    {
        new BugTest().runTest();
    }
    
    public void runTest()
    {
        try
        {
            Interface2 a = new Test();
            Interface2 b = ( Interface2 )a.clone();
            System.out.println( "Success" );
        }
        catch( Throwable xx )
        {
            xx.printStackTrace();
        }
    }
    
    private interface Interface1
    {
        public Object clone();
    }
    
    private interface Interface2 extends Interface1
    {
    }
    
    private class Test implements Cloneable, Interface2
    {
        private int m_junk = 0;
        
        public Object clone()
        {
            try
            {
                Test clone = ( Test )super.clone();
                clone.m_junk = m_junk;
                return( clone );
            }
            catch( CloneNotSupportedException xx )
            {
                throw new InternalError();
            }
        }
    }
}
(Review ID: 112883)
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