Differences between release and debug

[Guest]

Hi,

does anyone know what would be the (most common) reasons
to get difference answers in VC++.net between running in
release and debug ?

Thanks,

JC

[Carl Daniel [VC++ MVP]]

Re: Differences between release and debug

jean.cabello@ed s.com wrote:[color=blue]
> Hi,
>
> does anyone know what would be the (most common) reasons
> to get difference answers in VC++.net between running in
> release and debug ?[/color]

Reliance on content of uninitialized memory.

-cd

[Patrick Philippot]

Re: Differences between release and debug

jean.cabello@ed s.com wrote:[color=blue]
> Hi,
> does anyone know what would be the (most common) reasons
> to get difference answers in VC++.net between running in
> release and debug ?[/color]

For unmanaged code, the two main reasons for getting a different
behavior between release and debug versions are :

1/ The memory allocation mechanism. Unitialized or incorrectly
initiliazed pointers will be handled differently.

2/ Optimizations which are usually disabled in debug versions. For
example, my current project systematically crashes under Win9x when I
optimize for speed or size (I'm using VC6 for this one but the same
remarks apply). If I disable optimizations or use default optimization,
there's no problem. The same program runs fine in all cases under Win NT
+.

What differences are you observing?

--
Patrick Philippot - Microsoft MVP [.Net]
MainSoft Consulting Services

https://www.mainsoft.xx

(replace .xx with .fr when replying by e-mail)

[Guest]

Re: Differences between release and debug

I am seing exceptions thrown in release mode that do not
occur in debug mode.

The optimisation is critical as there is usually a factor
of 10 speed between release and debug. So my next question
is ...

Is there a compile flag in debug that will set all
uninitialised variable to invalid values and show where
the problem is ?

Thanks,


[color=blue]
>-----Original Message-----
>jean.cabello@e ds.com wrote:[color=green]
>> Hi,
>> does anyone know what would be the (most common) reasons
>> to get difference answers in VC++.net between running in
>> release and debug ?[/color]
>
>For unmanaged code, the two main reasons for getting a[/color]
different[color=blue]
>behavior between release and debug versions are :
>
>1/ The memory allocation mechanism. Unitialized or[/color]
incorrectly[color=blue]
>initiliazed pointers will be handled differently.
>
>2/ Optimizations which are usually disabled in debug[/color]
versions. For[color=blue]
>example, my current project systematically crashes under[/color]
Win9x when I[color=blue]
>optimize for speed or size (I'm using VC6 for this one[/color]
but the same[color=blue]
>remarks apply). If I disable optimizations or use default[/color]
optimization,[color=blue]
>there's no problem. The same program runs fine in all[/color]
cases under Win NT[color=blue]
>+.
>
>What differences are you observing?
>
>--
>Patrick Philippot - Microsoft MVP [.Net]
>MainSoft Consulting Services
>www.mainsoft.xx
>(replace .xx with .fr when replying by e-mail)
>
>
>
>.
>[/color]

[Doug Forster]

Re: Differences between release and debug

Hi,
[color=blue]
> Is there a compile flag in debug that will set all
> uninitialised variable to invalid values and show where
> the problem is ?[/color]

Debug does this by default I think. Which version of VS are you using? Does
your app still crash when you vary the optimization settings? I had similar
sounding problems which simply vanished with VS 2003

Cheers

Doug Forster

<jean.cabello@e ds.com> wrote in message
news:08ec01c3a9 47$4ba013a0$a00 1280a@phx.gbl.. .[color=blue]
> I am seing exceptions thrown in release mode that do not
> occur in debug mode.
>
> The optimisation is critical as there is usually a factor
> of 10 speed between release and debug. So my next question
> is ...
>
> Is there a compile flag in debug that will set all
> uninitialised variable to invalid values and show where
> the problem is ?
>
> Thanks,
>
>
>[color=green]
> >-----Original Message-----
> >jean.cabello@e ds.com wrote:[color=darkred]
> >> Hi,
> >> does anyone know what would be the (most common) reasons
> >> to get difference answers in VC++.net between running in
> >> release and debug ?[/color]
> >
> >For unmanaged code, the two main reasons for getting a[/color]
> different[color=green]
> >behavior between release and debug versions are :
> >
> >1/ The memory allocation mechanism. Unitialized or[/color]
> incorrectly[color=green]
> >initiliazed pointers will be handled differently.
> >
> >2/ Optimizations which are usually disabled in debug[/color]
> versions. For[color=green]
> >example, my current project systematically crashes under[/color]
> Win9x when I[color=green]
> >optimize for speed or size (I'm using VC6 for this one[/color]
> but the same[color=green]
> >remarks apply). If I disable optimizations or use default[/color]
> optimization,[color=green]
> >there's no problem. The same program runs fine in all[/color]
> cases under Win NT[color=green]
> >+.
> >
> >What differences are you observing?
> >
> >--
> >Patrick Philippot - Microsoft MVP [.Net]
> >MainSoft Consulting Services
> >www.mainsoft.xx
> >(replace .xx with .fr when replying by e-mail)
> >
> >
> >
> >.
> >[/color][/color]