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

OSR_Community_UserOSR_Community_User Member Posts: 110,217
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.


-----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 >=

??: Paul Bunn[SMTP:[email protected]]
?????: NT Developers Interest List
??????????: 21 ???? 2000 ?. 19:16
????: NT Developers Interest List
????: [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
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.


Paul Bunn,, 425-644-6000
Microsoft MVP - WindowsNT/2000

-----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 ???


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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