How to get the right offset of a bit field member in extension?

WINDBG
1

Hi all,

I am implementing a WinDBG extension, and I need to get the offset of a member which happend to be a bit field. It seems the documented functions provided by IDebugSymbols interface could only provide the offset at the byte level. Is there a possbile method I can use to get which bit it is as the “dt” command did.

Thanks.

2

What happens if you use GetFieldOffset with the bitfield member as the
last name in the dot separated string?

mm

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Sent: Wednesday, August 29, 2007 03:48
To: Kernel Debugging Interest List
Subject: [windbg] How to get the right offset of a bit field member in
extension?

Hi all,

I am implementing a WinDBG extension, and I need to get the offset of a
member which happend to be a bit field. It seems the documented
functions provided by IDebugSymbols interface could only provide the
offset at the byte level. Is there a possbile method I can use to get
which bit it is as the “dt” command did.

Thanks.

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3

Well, it just return me the offset to the byte that the bitfield member reside in.

Thanks.

4

Bummer. I guessed that’s probably you had tried originally, but wasn’t
sure, so I threw it out there. These problems are really frustrating,
because, most likely, there is a simple way to do it, but it is not
documented and involves some bizarre format string or whatnot. A while
back I got tired of symbol problems like these and wrote a library that
uses DIA to do the symbol management, and this is what my extensions
import. It was a huge pain in the ass, ass DIA is not, in my opinion,
user friendly, not very well documented, but does have a complete
example. I also use it mostly for non WinDbg related symbol processing
so, overall it was worth it, but still irritating.

Good luck,

mm

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
Sent: Wednesday, August 29, 2007 21:39
To: Kernel Debugging Interest List
Subject: RE:[windbg] How to get the right offset of a bit field member
in extension?

Well, it just return me the offset to the byte that the bitfield member
reside in.

Thanks.

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5

Thanks. Maybe I will look into it later, but it might not be an option
now. But still, thanks. Guess I have to change something now.

On 8/30/07, Martin O’Brien wrote:
> Bummer. I guessed that’s probably you had tried originally, but wasn’t
> sure, so I threw it out there. These problems are really frustrating,
> because, most likely, there is a simple way to do it, but it is not
> documented and involves some bizarre format string or whatnot. A while
> back I got tired of symbol problems like these and wrote a library that
> uses DIA to do the symbol management, and this is what my extensions
> import. It was a huge pain in the ass, ass DIA is not, in my opinion,
> user friendly, not very well documented, but does have a complete
> example. I also use it mostly for non WinDbg related symbol processing
> so, overall it was worth it, but still irritating.
>
> Good luck,
>
> mm
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@gmail.com
> Sent: Wednesday, August 29, 2007 21:39
> To: Kernel Debugging Interest List
> Subject: RE:[windbg] How to get the right offset of a bit field member
> in extension?
>
> Well, it just return me the offset to the byte that the bitfield member
> reside in.
>
> Thanks.
>
> —
> You are currently subscribed to windbg as: xxxxx@evitechnology.com
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