gcc/testsuite/gnat.dg/overflow_fixed.adb

   1 -- { dg-do run }
   2 -- { dg-options "-gnato -O" }
   3
   4 procedure Overflow_Fixed is
   5
   6   type Unsigned_8_Bit is mod 2**8;
   7
   8   procedure Fixed_To_Eight (Value : Duration) is
   9     Item : Unsigned_8_Bit;
  10   begin
  11     Item := Unsigned_8_Bit(Value);
  12     raise Program_Error;
  13   exception
  14     when Constraint_Error => null; -- expected case
  15   end;
  16
  17 begin
  18   Fixed_To_Eight (-0.5);
  19 end;