From: horst DOT kraemer AT snafu DOT de (Horst Kraemer)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: A bug
Date: Thu, 05 Aug 1999 03:38:15 GMT
Organization: [Posted via] Interactive Networx
Lines: 55
Message-ID: <37a89db7.28823536@news.snafu.de>
References: <199907290753 DOT JAA19712 AT aurora DOT put DOT poznan DOT pl>
NNTP-Posting-Host: n244-169.berlin.snafu.de
X-Newsreader: Forte Free Agent 1.11/32.235
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

On Thu, 29 Jul 1999 09:53:21 +0200 (MET DST), Wieslaw Bela
<wiechu AT aurora DOT put DOT poznan DOT pl> wrote:

>   I want to report a bug that I've  found while making a project in
> DJGPP. I don't know where is the problem, but I've tried many
> things, including changing the order of variables, size of arrays, their
> names (I also tried to compile on two different machines), and the effect
> is always the same: the memory for (static) array "wyglad" isn't
> allocated (when I debug it, size of this array is 0), although no bug is
> reported during the make (when I changed the program and allocated
> memory using new operator, everything was OK). I've got the same problem
> with COLOR_MAP structure from allegro, so it seems that DJGPP doesn't
> allocate memory for some structures.  Here is a short example of how
> does it work:
> 
> const MaxBok = 10, MaxWys = 20;
> const IlWierzch = 4, IlScian = 3;
> struct punkt2D
> {
> 	int x, y;
> };
> typedef punkt2D sciana [IlWierzch];
> 
> sciana wyglad [MaxBok + 1] [MaxBok + 1] [MaxWys + 1] [IlScian];
> 
> int main (void)
> {
> 	return 0;
> }



No bug.


Why should the compiler allocate something for the birds which is not
used in the program ? The program does nothing except returning 0 to
the host environment. For this effect it doesn't need to allocate an
array.

Change your program to

int main ()
{
        wyglad[0][0][0][0] = wyglad[0][0][0][1]
 	return 0;
}


and your 'wyglad' _will_ be allocated.


Regards
Horst