From: Martin Stromberg <eplmst AT lu DOT erisoft DOT se>
Message-Id: <200101231436.PAA03507@lws256.lu.erisoft.se>
Subject: Re: Debugging on 386
To: djgpp-workers AT delorie DOT com
Date: Tue, 23 Jan 2001 15:36:40 +0100 (MET)
In-Reply-To: <3405-Mon22Jan2001221957+0200-eliz@is.elta.co.il> from "Eli Zaretskii" at Jan 22, 2001 10:19:58 PM
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> > -> c
> > Breakpoint 1, main (argc=1, argv=0x905d4) at analyse_ints.c:129
> > 129       if( argc != 2)
> > -> bt
> > #0  main (argc=1, argv=0x905d4) at analyse_ints.c:129
> > #1  0x3368 in __crt1_startup ()
> > -> n
> > Exiting due to signal SIGFPE
> 
> This one is not.  What does "disassemble analyse_ints" print near the
> EIP of the breakpoint (0x1a64)?  Do you see any FP instructions
> anywhere around that?

Nope. 00001a64 is a "cmpl" instruction. I'm at work now but I'll mail
back the disassembly later.

> > Coprocessor Error at eip=00001a64, x87 status=
> > Program received signal SIGEMT, Emulation trap.
> > 0x9611 in _status87 ()
> > -> bt
> > #0  0x9611 in _status87 ()
> > #1  0x47da in do_faulting_finish_message ()
> > #2  0x4d13 in __djgpp_traceback_exit ()
> > #3  0x4da0 in raise ()
> > #4  0x2c3a in nofpsig ()
> > #5  0x4daa in raise ()
> > #6  0x4e07 in __djgpp_exception_processor ()
> > #7  0x1 in ?? ()
> > #8  0x3368 in __crt1_startup ()
> 
> This is expected: the code which prints the traceback calls
> _status87.  But what is that 0x1 on the stack?

Yes...?

> Not bad at all: it eventually got to printing the crash message and
> exiting the program ``almost normally''.

Well, the first mystery is the SIGFPE. There shouldn't be any SIGFPE
signals coming at all...

> You are welcome to work on this, if you feel like it.  I'd be happy to
> give directions if you do.

Please direct me.


Right,

						MartinS