From: su-lin DOT liao AT worldnet DOT att DOT net (Eric Liao)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Help with errors
Date: Tue, 08 Jul 1997 22:10:28 GMT
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On Tue, 08 Jul 1997 10:27:56 -0700, Eric Lange <ericl AT emu DOT com> wrote:

>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


	I'm pretty sure destx and desty are correct, because my game
runs when I compile it in Borland Turbo C++ 3.1.  I'm still new to
DJGPP, though.  I'll try using GDB I guess.  

	Eric Liao