Re: Pointer to int and vice versa

I have gone that road (DTAMDL(*LLP64) with another project (which ain't finished yet) and it was aweful. It worked but I had to changed very much of the code which would not be necessary if I could just use the 128 data model.

Using 64bit data model would be my last choice atm.

But thanx.

Mihael

-----Original Message-----
From: c400-l-bounces+mihael.schmidt=rossmann.de@xxxxxxxxxxxx [mailto:c400-l-bounces+mihael.schmidt=rossmann.de@xxxxxxxxxxxx] On Behalf Of Mark S. Waterbury
Sent: Friday, December 03, 2010 2:54 PM
To: C programming iSeries / AS400
Subject: Re: [C400-L] Pointer to int and vice versa

Mihael:

This is precisely the problem of "storing a pointer in an integer."
(Those macros "cast" a pointer to an integer and vice versa.)

Create your C modules, programs or service programs to run "teraspace
enabled" and use only 64-bit pointers. That way, it is possible to
"cast" an integer to a pointer and vice versa, and to store a pointer in
an integer.

Use the ILE C compiler options DTAMDL(*LLP64) STGMDL(*TERASPACE)
TERASPACE(*YES *TSIFC) on the CRTCMOD or CRTBNDC commands.

Hope that helps,

Mark S. Waterbury

On 12/3/2010 5:04 AM, Schmidt, Mihael wrote:
Hi,

I am just in the process of (again) trying to port another C lib to the ILE environment. In C it seems common to return an integer via a pointer.

#include<stdlib.h>
#include<stdio.h>

typedef int gint;
typedef unsigned int guint;
typedef void* gpointer;
#define GPOINTER_TO_INT(p) ((gint) (p))
#define GPOINTER_TO_UINT(p) ((guint) (p))
#define GINT_TO_POINTER(i) ((gpointer) (i))
#define GUINT_TO_POINTER(u) ((gpointer) (u))


main ()
{
gint x = 358;
gpointer p = GINT_TO_POINTER(x);
gint y = GPOINTER_TO_INT(p);
printf("%i", y);
}

Is this safe to do on IBM i as normally pointers are 16 bytes on IBM i instead of 4 bytes as on most PC Systems.

(The question is not about storing a pointer in an integer as I know that this is not possible because of the size differences.)

Regards

Mihael Schmidt
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