[Bug java/16431] New: Bytecode compiler silently generates incorrect code

["aph at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

With some oddly formed class files, the bytecode compiler can spuriously
generate additional DECLs for local variable slots, and these DECLs have
undefined initial values.  This is a regression caused by the tree-SSA merge.

The problem arises when there are two different types put onto the stack at
different points in the execution.  This generates two DECLs, one for each type.
 Later code that refers to that stack item can do so with a type that is a
common superclass of the two types, but we have generated two separate DECLs.

The only way properly to fix this is to change the way that stack items are
mapped on to DECLs.

-- 
           Summary: Bytecode compiler silently generates incorrect code
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: java
        AssignedTo: aph at gcc dot gnu dot org
        ReportedBy: aph at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16431