Date: Thu, 4 May 2000 12:44:52 +0200 (MET DST)
From: pad2369 <pad2369 AT iperbole DOT bologna DOT it>
Message-Id: <200005041044.MAA17219@maggiore.iperbole.bologna.it>
To: Alexandre Devaure <Alexandre DOT Devaure AT leroy-autom DOT com>
Cc: djgpp AT delorie DOT com
References: <Pine DOT SUN DOT 3 DOT 91 DOT 1000504092557 DOT 16176B-100000 AT is> <005b01bfb593$eb5b1c60$3eefa8c0 AT leroyautom DOT com>
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Sender: pad2369 AT iperbole DOT bologna DOT it
Subject: Re: structures size
Reply-To: djgpp AT delorie DOT com

Alexandre Devaure <Alexandre DOT Devaure AT leroy-autom DOT com>:
> Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
> > On Wed, 3 May 2000, Alexandre Devaure wrote:
> >
> > > I'd like the size of my structures is the same 
that in Borland C
> because
> my
> > > program need to read a structure in flash written 
by a program
> developed
> > > under Borland C. So, I want to use the -fpack-
struct option at
> compilation
> > > time. But it has no effect on the structure size 
and I need to add the
> > > packed attribute on each structure.
> >
> > C programs or C++ programs?
> >
> > Can you post a short test program and its 
compilation command line, which
> > can be used to reproduce this problem?
> >
>
>
> This is a C program :
>
> #include <stdio.h>
>
> struct l {
>         uchar c;
>         uint o;
>         uint s;
> };
> struct st {
>         struct l l;
>         ulong d;
>         uchar i;
>         uchar t;
>         ulong n;
> };
>
> main()
> {
>         printf("%d\n",sizeof(struct st));
> }
>
> the command line is gcc -fpack-struct file.c

Quoting section 22.11 of the FAQ list (v2.30):

  GCC 2.95.1 and 2.95.2 had bugs in their support of 
  -fpack-struct (the bug is corrected in v2.96 and   
  later). 
 
It seems you need to upgrade to latest gcc, otherwise 
you must use __attribute__((packed)) for each struct
in stead of -fpack-struct on command line...

ciao
  Giacomo
---------------------------------------------------
Giacomo Degli Esposti - pad2369 AT iperbole DOT bologna DOT it