Re: Help needed - "Storage_Error stack overflow or erroneous memory access"

[reinert <reinkor@gmail.com>]

OK, for those having interest:

I have somehow sorted out the problem. 
The lesson learned is that I may have done something wrong when using "with invariant .." and the compiler error message could be more helpful for programmers like me :-) 

Here is a test program illustrating. It compiles without error on my debian 8.8 (jessie) machine, but the debian 9 (stretch) gives a cryptic error message.
Could anybody confirm? And maybe elaborate?

with frame1;         use frame1;
procedure c0 is
   df : df_t;
begin
   df.center0 (True);
end c0;

-- package:

with Ada.Numerics.Generic_Real_Arrays;

package frame1 is

   subtype real is float;

   package gra is new Ada.Numerics.Generic_Real_Arrays (real);
   use gra;

   type frame_t is tagged private;

   procedure center0 (frame : in out frame_t; b : Boolean);

   type df_t is new frame_t with private;

private

   type frame_t is tagged record
      a, b                           : Boolean := False;
      r_a, r_b                       : real_vector(1..2);
      set_modus                      : Boolean := False;
      dynamic_frame1, dynamic_frame2 : real_vector (1 .. 2);
      center0                        : Boolean := False;
      active1                        : Boolean := False;
      w1,w2                          : real_vector(1..2);
   end record with
       type_invariant =>
             ((if
               frame_t.set_modus
         then
           frame_t.dynamic_frame1 (1) <= frame_t.dynamic_frame2 (1) and
           frame_t.dynamic_frame1 (2) >= frame_t.dynamic_frame2 (2)));

   type df_t is new frame_t with record
      focus1 : Boolean              := False;
   end record;

end frame1;

package body frame1 is

   procedure center0 (frame : in out frame_t; b : Boolean) is
   begin
      frame.center0 := b;
   end center0;

end frame1;




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