Re: Memory limits in Ada where Fortran has none

["braver" <deliverable@gmail.com>]

Now, this is an interesting experiment:

Fortran:
C-----
      PARAMETER (NMAX=100 000 000)
      COMMON /CA/A
      INTEGER A
      DIMENSION A(NMAX)
      END
C-----

Ada: we have a package Lord_Fortran and the main procedure Import:

package Lord_Fortran is
   A: array (Positive range 1..67_000_000) of Integer;
   pragma Import(Fortran, A, "ca_");
   pragma Suppress(Index_Check, On=> A);
end Lord_Fortran;

with Text_IO; use Text_IO;
with Lord_Fortran; use Lord_Fortran;
procedure Import is
   package IO_Integer is new Integer_IO(Integer); use IO_Integer;

   NMAX: constant Positive := 100_000_000;

   S: Natural := 0;

   pragma Suppress(All_Checks, A);

begin
   Put_Line("Lord Fortran, we bow before thee!");

   for I in 1..NMAX loop
      A(I) := I;
      if I mod 1_000_000 = 0 then
         Put('.');
         -- Put(I);
      end if;
   end loop;
   New_Line;
   Put_Line("Allright!");

   S := A(68_000_000);

   Put(Integer'Image(S));
   New_Line;
end Import;

Depending on the index value at (1), I get the following results...
When running as above:

alexy@angle:/bk/ada/import > ./import
Lord Fortran, we bow before thee!
....................................................................................................
Allright!

raised CONSTRAINT_ERROR : import.adb:25

(There's a hundred dots, as expected!)

If the index is NMAX, then (same as above but the exception):
...
Allright!

raised STORAGE_ERROR : stack overflow (or erroneous memory access)

When 67_000_000, prints it.  Strangely, doesn't come close enough to
67_108_864...

Cheers,
Alexy