From: Eric Lange <ericl AT emu DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Help with errors
Date: Tue, 08 Jul 1997 10:27:56 -0700
Organization: E-mu Systems, Inc.
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Message-ID: <33C2789C.5887@emu.com>
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Eric Liao wrote:
> 
>         OK, I finally ported my game to DJGPP, and it compiled, and
> made an executable.  When I run the executable, though it crashes, and
> the SYMIFY output looks like this:
> 
> General Protection Fault at eip=00005f4a
> eax=a5dd0e43 ebx=0024d0e0 ecx=00003e01 edx=a5de8d7c esi=00000054
> edi=0004bac0
> ebp=0024ba8c esp=0024b9d0 program=C:\FLAME\FLAME.EXE
> cs: sel=00a7  base=82ac4000  limit=0047bfff
> ds: sel=00af  base=82ac4000  limit=0047bfff
> es: sel=00af  base=82ac4000  limit=0047bfff
> fs: sel=0087  base=0000df40  limit=0000ffff
> gs: sel=00bf  base=00000000  limit=ffffffff
> ss: sel=00af  base=82ac4000  limit=0047bfff
> 
> Call frame traceback EIPs:
>   0x00005f4a   _write_numbers__Fv+542, line 352 of flame.cc
>   0x0000c82c   _main+100, line 1507 of flame.cc
>   0x0000cf56   ___crt1_startup+138
> 
>         I look at the line it refers to and all it is a declaration of
> a temporary int to equal an element in an array like
>   int temp=map[desty*320+destx];
> where desty and destx are just coords.  Map is a 64K array.  What
> possible error could this be?  I thought it might be some kind of
> stack error so I used stubedit and gave it a 2 meg stack but it still
> had the same error.  Any help would be appreciated.

Is it possible that desty or destx have erroneous values?  A moderately
huge value of desty would overrun the bounds of your DS, which is 4.7MB
in size.  This would easily cause a GPF.  Try stepping through using GDB
when you get to this point.

Eric Lange