gdb/testsuite/gdb.ada/unchecked_union/unchecked_union.adb

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  15
  16 with System;
  17 with Pck; use Pck;
  18
  19 procedure Unchecked_Union is
  20    type Key is (Alpha, Beta, Omega);
  21
  22    type Inner(Disc : Key := Omega) is record
  23       case Disc is
  24          when Alpha =>
  25             Small : Integer range 0..255;
  26             Second : Integer range 0..255;
  27          when Beta =>
  28             Bval : Integer range 0..255;
  29          when others =>
  30             Large : Integer range 255..510;
  31             More : Integer range 255..510;
  32       end case;
  33    end record;
  34    pragma Unchecked_Union (Inner);
  35
  36    type Outer(Disc : Key := Alpha) is record
  37       case Disc is
  38          when Alpha =>
  39             Field_One : Integer range 0..255;
  40          when others =>
  41             Field_Two : Integer range 255..510;
  42       end case;
  43    end record;
  44    pragma Unchecked_Union (Outer);
  45
  46    type Pair is record
  47       Pone : Inner;
  48       Ptwo : Outer;
  49    end record;
  50
  51    Value : Pair;
  52
  53 begin
  54    Do_Nothing (Value'Address);          -- BREAK
  55 end Unchecked_Union;