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RE: Can we declare a variable as 'int' in the driver???

OSR_Community_UserOSR_Community_User Member Posts: 110,217
Thanx for all the responses....

The free build driver loads if I make the loop condition as iCount >
-1. [The
loop comes out once iCount becomes -ve]. Now I'm trying to see the
assembly code
difference in both free and checked build. I can easily get that in
Checked
build as I can put a break point on the for loop and see the m/c code
from
WinDbg. But how can I get the m/c code if it is free build ? Any help
is
appriciated....

-Esha


Duncan Hume wrote:

> One thing to bear in mind is that the storage is irrelevant, it is the
> functions/macnine code instructions that determine if you are working in
> signed or unsigned. Check the machine code listing to see if the
> instructions used in the Free build looks the same as the Checked.. Try
> changing the loop to >-1 and see what code is produced.
>
> Duncan
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: 21 June 2000 16:33
> To: NT Developers Interest List
> Subject: [ntdev] RE: Can we declare a variable as 'int' in the driver
> ???
>
> >I don't see what difference iCount being signed or not
> When a I used to be a pupil I was given a task by my teacher to find a bug
> in this code:
>
> ULONG uCount;
> for(uCount = 10; uCount >= 0; uCount--)
> {
> // ...
> }
>
> And I've found it then :) This loop is infinite, 'cause uCount is always >=
> 0.
>
> ----------
> ïÔ: Paul Bunn[SMTP:[email protected]]
> ïÔ×ÅÔ: NT Developers Interest List
> ïÔÐÒÁ×ÌÅÎÏ: 21 ÉÀÎÑ 2000 Ç. 19:16
> ëÏÍÕ: NT Developers Interest List
> ôÅÍÁ: [ntdev] RE: Can we declare a variable as 'int' in the driver ???
>
> I don't see what difference iCount being signed or not would make to the for
> loop.
> int normally is equivalent to LONG. You should be able to define iCount as
> LONG or ULONG and it shouldn't make any difference to that particular loop.
> The only difference I can think of is that in the free build it is likely
> that iCount may not be assigned storage at all, but may just live as a
> register value (depending on what you're doing with it). It's also possible
> that it's a compiler bug, though that is rare these days. I would tend to
> recommend debugging the free build and looking at the disassembly.
>
> Regards,
>
> Paul Bunn, UltraBac.com, 425-644-6000
> Microsoft MVP - WindowsNT/2000
> http://www.ultrabac.com
>
>
> -----Original Message-----
> From: Eshanye [mailto:[email protected]]
> Sent: Wednesday, June 21, 2000 7:27 AM
> To: NT Developers Interest List
> Subject: [ntdev] Can we declare a variable as 'int' in the driver ???
>
> Hi,
>
> I have declared a variable as 'int' in my driver. This variable is used
> as an index inside a for loop. something like this:-
>
> int iCount;
>
> for(iCount = 3; iCount >= 0; iCount--)
> {
>
> blah.. blah..
>
> }
>
> This is a part of DriverEntry....
>
> Now this driver is working very fine if built as a checked build. But it
> wont get loaded if it is built as a free build. Because iCount is
> behaving as ULONG. and therefore it is in an infinite loop and so the
> driver is not getting loaded at all.
>
> [I know that I can change the for loop to serve my purpose, but ...
> why...]. I declared iCount as LONG. But still the same behavior !!!!!
> [LONG is supposed to be signed long right ????] What is happening ?
>
> ---
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