Name: wm7046 Date: 06/04/97


Sample Program

The following application demonstrates the behavior.


class Scope
{
   public static void main(String[] args)
   {
      {
         int i;

         i = 55;
         System.out.println("i = " + i);
      }

      {
         int i;

         i = 99;
         System.out.println("i = " + i);
      }
   }
}



The Problem

Here's the corresponding output from javap -l:


Compiled from Scope.java
synchronized class Scope extends java.lang.Object
    /* ACC_SUPER bit set */
{
    public static void main(java.lang.String[]);
    Scope();
}

Line numbers for method void main(java.lang.String[])
   line 8: 0
   line 9: 3
   line 15: 25
   line 16: 28
   line 3: 50

Local variables for method void main(java.lang.String[])
   java.lang.String[] args pc=0, length=51, slot=0
   int i pc=3, length=48, slot=1
   int i pc=28, length=23, slot=2

Line numbers for method Scope()
   line 1: 0

Local variables for method Scope()
   Scope this pc=0, length=5, slot=0



The compiler-generated information has address ranges for the two variables named i which overlap. The first entry for i should have a length of 22, not 48. Without a fix to this problem, a debugger has no way of distinguishing between the two variables named i once the second one comes into scope.
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