Re: Possible compiler bug with this simple program

[Jerry <lanceboyle@qwest.net>]

On Aug 29, 9:47 pm, Jerry <lancebo...@qwest.net> wrote:
> On Aug 29, 6:00 pm, "Randy Brukardt" <ra...@rrsoftware.com> wrote:
> > "Jerry" <lancebo...@qwest.net> wrote in message
>
> > >FWIW, in the _real_ application that I am working on, plmap is written
> > >in C (and accessed from my binding by an Import).
>
> > Interestingly, that's completely different. That *should* work on all Ada
> > compilers (note that the wording specifically excludes unconstrained
> > parameters for pragma Import).
   <snip>
> >                                          Randy.
>
> I'll see if I can make another example where plmap is a simple program
> in C that is Import-ed and see if it bombs on a 64-bit computer.
>
> Jerry

I've changed the simple example so that plmap is implemented in C.

The results are the same as with the all-Ada version: It runs OK on my
OS X 10.4.11 machine, PPC, Ada 4.3, but my colleague reports that it
crashes on his 64-bit machine which I believe is still the 64-bit
Intel Duo running Debian lenny and GNAT 4.3.1-2. The crash looks the
same as before:

raised STORAGE_ERROR : stack overflow (or erroneous memory access)

The example as either a zip or tarball which includes the very short
code files and a three-line bash script can be downloaded from my site
here:

http://public.me.com/oscarruitt

or directly here:

http://public.me.com/oscarruitt/simple_test_case_with_c.zip
http://idisk.mac.com/oscarruitt-Public/simple_test_case_with_c.zip

(Let me know if these don't work.)

And here is the code directly:


-- x19a_temp.adb

with
    type_declaration,
    Ada.Text_IO;
use
    type_declaration,
    Ada.Text_IO;

procedure x19a_temp is

    procedure mapform19(n : Integer; x : in out Real_Vector);
    pragma Convention(C, mapform19);

    procedure mapform19(n : Integer; x : in out Real_Vector) is
    begin
        for i in 0 .. n - 1 loop
            x(i) := Long_Float(i);
            Put_Line(Long_Float'image(x(i)));
        end loop;
    end mapform19;

begin
    plmap(mapform19'Unrestricted_Access);
end x19a_temp;



-- type_declaration.ads

package type_declaration is

    type Real_Vector is array (Integer range <>) of Long_Float;

    type Map_Form_Function_Pointer_Type is access
        procedure (Length_Of_x : Integer; x : in out Real_Vector);
    pragma Convention(Convention => C, Entity =>
Map_Form_Function_Pointer_Type);

    procedure plmap(Map_Form_Function_Pointer :
Map_Form_Function_Pointer_Type);
    pragma Import(C, plmap, "plmap");

end type_declaration;



/* plplot.h */

#include <stdint.h>
void plmap( void (*mapform)(int32_t, double *));



/* plmap.c */

#include "plplot.h"
void plmap( void (*mapform)(int32_t, double *) )
{
    int32_t n;
    double xx[10];
    n = 10;
    (*mapform)(n, xx);
}


# Compile and run with these lines:

gcc -c plmap.c
gnatmake x19a_temp.adb -largs plmap.o
./x19a_temp


Thanks once again.

Jerry