java/1328: Definate assignment with switch

[bryce@albatross.co.nz]

>Number:         1328
>Category:       java
>Synopsis:       Definate assignment with switch
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apbianco
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Dec 20 12:19:04 PST 2000
>Closed-Date:    
>Last-Modified:  Sun Dec 10 16:16:00 PST 2000
>Originator:     Bryce McKinlay
>Release:        unknown-1.0
>Organization:
>Environment:
any
>Description:
The following example is illegal because 'r' may not have
been assigned when it is concatenated. gcj does not pick 
up this error.

public class Definate
{
  int id = 2;
  
  void a()
  {
    String r;
    
    switch (id)
      {
        case 99:
	  r = "foo";
	break;
      }
    
    r += "bar";
  }
}
>How-To-Repeat:
Compile the example above.
>Fix:

>Release-Note:
>Audit-Trail:

Formerly PR gcj/304


From: Bryce McKinlay <bryce@albatross.co.nz>
To: java-gnats@sourceware.cygnus.com
Cc:  
Subject: Re: gcj/304: Definate assignment with switch
Date: Mon, 11 Dec 2000 13:09:01 +1300

 bryce@albatross.co.nz wrote:
 
 > The following example is illegal because 'r' may not have
 > been assigned when it is concatenated. gcj does not pick
 > up this error.
 
 Here's another similar situation where gcj fails to report a
 lack-of-definate-assignment error:
 
 public class DefinateAssign
 {
   DefinateAssign next;
 
   public Object a()
   {
     DefinateAssign e;
     if (next != null)
       e = next;
 
     if (e == null)
       {
  e = new DefinateAssign();
       }
     return e;
   }
 }
 
 In this case "e" can end up being a garbage pointer, which will cause
 weird crashes elsewhere. I got tripped up by this badly, guess I
 should have tried to compile with jikes ;-)
 
   [ bryce ]
 
 
>Unformatted: