Message-Id: <200006202008.XAA23539@mailgw1.netvision.net.il>
Date: Tue, 20 Jun 2000 23:09:27 +0200
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From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
To: Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
CC: djgpp AT delorie DOT com
In-reply-to: <394F7467.6340126B@phekda.freeserve.co.uk> (message from Richard
	Dawe on Tue, 20 Jun 2000 14:40:55 +0100)
Subject: Re: preprpcessor for overiding gcc optimation switch
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> From: Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
> Newsgroups: comp.os.msdos.djgpp
> Date: Tue, 20 Jun 2000 14:40:55 +0100
> 
> When I have done debugging on libsocket, I found that normal breakpoints
> failed to work sometimes. I found that hardware breakpoints were much more
> successful - e.g. "hb lsck_init". Otherwise gdb would not stop in the
> routine that I asked it to. I guessed that this was some problem due to
> libsocket calling in Windows virtual device drivers.

I fail to see how calling a VxD can disable a breakpoint.  A
breakpoint is a special instruction written to the program's code;
unless Windows is smart enough to remove that special instruction and
replace it with the original one, it can do nothing to interfere.