gcc/testsuite/gnat.dg/unchecked_convert12.adb

   1 -- { dg-do run }
   2
   3 with Unchecked_Conversion;
   4
   5 procedure Unchecked_Convert12 is
   6
   7   subtype Unsigned_Type is Integer range 2_034 .. 2_164;
   8
   9   subtype Signed_Type is Integer range -2048 .. 2047;
  10
  11   type Rec is record
  12     S : Unsigned_Type;
  13   end record;
  14   pragma Pack (Rec);
  15
  16   function To_Signed_Type is
  17      new Unchecked_Conversion (Source => Rec, Target => Signed_Type);
  18
  19   function To_Unsigned_Type is
  20     new Unchecked_Conversion (Source => Signed_Type, Target => Rec);
  21
  22   Data : Signed_Type;
  23   Temp : Rec;
  24
  25 begin
  26
  27   Data := -1996;
  28   Temp := To_Unsigned_Type (Data);
  29   if Temp.S /= 2100 then
  30     raise Program_Error;
  31   end if;
  32   Data := To_Signed_Type (Temp);
  33   if Data /= -1996 then
  34     raise Program_Error;
  35   end if;
  36
  37   Data := 2047;
  38   Temp := To_Unsigned_Type (Data);
  39   if Temp.S /= 2047 then
  40     raise Program_Error;
  41   end if;
  42   Data := To_Signed_Type (Temp);
  43   if Data /= 2047 then
  44     raise Program_Error;
  45   end if;
  46
  47 end;