gcc/testsuite/gnat.dg/unchecked_convert2.adb

   1 -- { dg-do run }
   2
   3 with Ada.Unchecked_Conversion;
   4 with Ada.Streams; use Ada.Streams;
   5 with Ada.Text_IO; use Ada.Text_IO;
   6
   7 procedure Unchecked_Convert2 is
   8
   9    subtype Day_Number is Integer range 0 .. 31;
  10
  11    subtype Byte_Array_Of_Integer is Stream_Element_Array
  12      (1 .. Integer'Size / Stream_Element_Array'Component_Size);
  13
  14    function To_Byte_Array is
  15       new Ada.Unchecked_Conversion (Integer, Byte_Array_Of_Integer);
  16
  17    Day_Now : Day_Number;
  18    Pragma Volatile (Day_Now);
  19
  20    Arr : Stream_Element_Array (1 .. 12) := (others => 16#ff#);
  21
  22    procedure Test (Arr : Stream_Element_Array) is
  23    begin
  24       if Arr(5) /= 0 or Arr(6) /= 0 or Arr(7) /= 0 or Arr(8) /= 0 then
  25          raise Program_Error;
  26       end if;
  27    end;
  28
  29 begin
  30    Day_Now := 0;
  31    Arr (5 .. 8) := To_Byte_Array (Day_Now);
  32    Test (Arr);
  33    Arr (1) := 16#ff#;
  34 end Unchecked_Convert2;