[Bug ada/23354] New: Normalize_Scalars and enumeration types with holes

[fw at deneb dot enyo dot de]

Objects are unnecessarily initialized to valid values.  The initialization
algorithm is described here:

`Enumeration types'
     Objects of an enumeration type are initialized to all one-bits,
     i.e. to the value `2 ** typ'Size - 1' unless the subtype excludes
     the literal whose Pos value is zero, in which case a code of zero
     is used. This choice will always generate an invalid value if one
     exists.

But the conclusion is wrong because it does not consider enumeration types with
holes.

--  Run through gnatchop.  Compile with -O2.
pragma Normalize_Scalars;

with Ada.Text_IO; use Ada.Text_IO;

procedure Bug4 is
   type T is (A, B);
   for T use (A => 1, B => 255);
   for T'Size use 8;

   X : T;

begin
   if X'Valid then
      Put_Line ("FAIL");
   else
      Put_Line ("PASS");
   end if;
end Bug4;

-- 
           Summary: Normalize_Scalars and enumeration types with holes
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fw at deneb dot enyo dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23354